Polar research: Reports and findings

Reindeer thrive on forest diversity

(Bjørnhild Fjeld/ScienceNordic, 8 April 2013) -- Modern forestry techniques are like plantations, with a homogenous blend of trees covering vast areas. Old and young trees rarely stand together. The quest for profit and efficiency has brought this about. But there are downsides - one being that the ecosystem becomes more vulnerable to changes. Monoculture forestry depletes forest fauna.

Tim Horstkotte of the University of Umeå’s Department of Ecology and Environmental Sciences has studied the interaction of reindeer husbandry and forestry in North Sweden. According to his study modern forestry makes it harder for reindeer to find food during extreme chills. Horstkotte asserts that a diversity in forest landscapes with a larger share of old growth and more variation in trees is indispensable to a viable reindeer husbandry sector.

“In contrast to monocultures, a mix of different species gives reindeer owners leeway for reacting to changes in winter grazing areas.” “They can alternative sites to find accessible forage for their reindeer when lichen availability is poor in certain types of forest,” says Horstkotte. Terrestrial lichen - growing low on the ground - tops the list of reindeer food through winter. So the researcher monitored snow conditions and studied how this affected access to forage in different types of forest.

This led to the discovery that young and old forest offer different kinds of grazing the animals. Horstkotte stresses that forests must be allowed to mature for a long time, so slow-growing arboreal lichens have a chance to get established. It serves as a supplemental forage for reindeer during winter, especially in periods with a hard snow crust on the ground, when it is hard for the animals to break through to terrestrial lichens.Horstkotte thinks that decisions regarding the exploitation of forests should give more attention to the social and cultural values of ecosystems.


Posted by Amanda Graham – 17 April 2013; 10:57:29 AM – Permalink  

Canadian Arctic glacier melt accelerating, irreversible, projections suggest

(American Geophysical Union press release via Science Daily, 12 March 2013) -- Ongoing glacier loss in the Canadian high Arctic is accelerating and probably irreversible, new model projections by Lenaerts et al., suggest. The Canadian high Arctic is home to the largest clustering of glacier ice outside of Greenland and Antarctica -- 146,000 square kilometers (about 60,000 square miles) of glacier ice spread across 36,000 islands.

In the past few years, the mass of the glaciers in the Canadian Arctic archipelago has begun to plummet. Observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellites suggest that from 2004 to 2011 the region's glaciers shed approximately 580 gigatons of ice. Aside from glacier calving, which plays only a small role in Canadian glacier mass loss, the drop is due largely to a shift in the surface-mass balance, with warming-induced meltwater runoff outpacing the accumulation of new snowfall. ...

The authors calculate that by 2100, when the Arctic archipelago is 6.5 Kelvin (14 degrees Fahrenheit) warmer, the rate of glacier mass loss will be roughly 144 gigatons per year, up from the present rate of 92 gigatons per year. In total, the researchers expect Canadian Arctic archipelago glaciers to lose around 18 percent of their mass by the end of the century. Given current warming trends, they suggest that the ongoing glacier loss is effectively irreversible.


Posted by Amanda Graham – 12 March 2013; 8:08:35 PM – Permalink  

Arctic scientists see Canada slipping on world stage

(Kate Allen Science/Technology World, Toronto Star, 12 March 2013) -- In Germany, in New Zealand, in the Canary Islands and at 21 other observatories around the world, instruments called infrared spectrometers are teasing apart sunlight to measure greenhouse gas levels in the Earth’s atmosphere. Two dozen spectrometers make up the Total Carbon Column Observing Network (TCCON). The one in Eureka, Nunavut, is the most northerly of them all — a sentry in the Arctic, where extreme effects of climate change are rapidly altering the environment.

“They see our site at Eureka as being a key site,” says University of Toronto atmospheric physicist Kimberly Strong, who oversees the instrument. Last April, federal funding to Eureka lab dried up; the spectrometer dropped from 150 measurement days a year to around 30. The Arctic is a core part of this country’s identity, and Prime Minister Stephen Harper is eager to assert Canada’s sovereignty in the North. Last Thursday, the government signed a $288-million shipbuilding contract for new Arctic patrol vessels. Yet increasingly, the basic science that would let us understand changes occurring in our own backyard — and either mitigate or take advantage of them — is being neglected by Canada and assumed by other countries, Arctic researchers say.

“If we Canadians don’t do the work, it’s not like other people are just going accept that internationally,” says Antoni Lewkowicz, a permafrost scientist at the University of Ottawa. “You can only so often have maps presented at conferences of the circumpolar area and big blanks gaps over Canada before the people who are in Sweden or Germany say, ‘Oh, well I guess somebody better do that work, then.’”


Posted by Amanda Graham – 12 March 2013; 7:52:14 PM – Permalink  

Siberian fossil revealed to be one of the oldest known domestic dogs

(PLoS press release via EurekAlert!, 6 March 2013) -- Analysis of DNA extracted from a fossil tooth recovered in southern Siberia confirms that the tooth belonged to one of the oldest known ancestors of the modern dog, and is described in research published March 6 in the open access journal PLOS ONE by Anna Druzhkova from the Institute of Molecular and Cellular Biology, Russian Federation, and colleagues from other institutions.

Human domestication of dogs predates the beginning of agriculture about 10,000 years ago, but when modern dogs emerged as a species distinct from wolves is still unclear. Although some previous studies have suggested that this separation of domestic dogs and wolves occurred over 100,000 years ago, the oldest known fossils of modern dogs are only about 36,000 years old.

The new research published today evaluates the relationship of a 33,000 year old Siberian fossil to modern dogs and wolves based on DNA sequence. The researchers found that this fossil, named the 'Altai dog' after the mountains where it was recovered, is more closely related to modern dogs and prehistoric canids found on the American continents than it is to wolves. They add, "These results suggest a more ancient history of the dog outside the Middle East or East Asia, previously thought to be the centers where dogs originated." [doi: 10.1371/journal.pone.0057754]


Posted by Amanda Graham – 10 March 2013; 7:24:13 PM – Permalink  

Significant reduction in temperature and vegetation seasonality over northern latitudes

(Woods Hole Research Center press release via EurekAlert!, 10 March 2013) -- An international team of authors from 17 institutions in seven countries, including the Woods Hole Research Center, published a study in the journal Nature Climate Change on the 10 March 2013 (10.1038/NCLIMATE1836: http://www.nature.com/nclimate). The study shows that, as the cover of snow and ice in the northern latitudes has diminished in recent years, the temperature over the northern land mass has increased at different rates during the four seasons, causing a reduction in temperature and vegetation seasonality in this area. The temperature and vegetation at northern latitudes increasingly resemble those found several degrees of latitude farther south as recently as 30 years ago.

The NASA-funded study, based on newly improved ground and satellite data sets, examines critically the relationship between changes in temperature and vegetation productivity in northern latitudes. "The amplified warming in the circumpolar area roughly above the Canada-USA border is reducing temperature seasonality over time because the colder seasons are warming more rapidly than the summer," says Liang Xu, a Boston University doctoral student and lead co-author of the study. As a result of the enhanced warming over a longer ground-thaw season, the total amount of heat available for plant growth in these northern latitudes is increasing—creating large patches of vigorously productive vegetation totaling more than a third of the northern landscape—over 9 million km2, which is roughly about the area of the USA.

A key finding of this study is an accelerating greening rate in the Arctic and a decelerating rate in the boreal region, despite a nearly constant rate of temperature seasonality diminishment in these regions over the past 30 years. ... The authors measured seasonality changes using latitude as a yardstick. They first defined reference latitudinal profiles for the quantities being observed and then quantified changes in them over time as shifts along these profiles.


Posted by Amanda Graham – 10 March 2013; 6:56:00 PM – Permalink  

Sea ice regulates greenhouse gases on land

(Sybille Hildebrandt/ScienceNordic, 19 February 2013) -- Global warming causes the sea ice to shrink, and the melting plays a much greater part in the ability of continents and oceans to absorb and release greenhouse gases than previously thought. So concludes a Nordic research group after having reviewed the relevant scientific literature.

”The key message from science is that the current disappearance of the sea ice will play a major part in the exchange of greenhouse gases in the Arctic region. The melting not only affects the sea’s ability to absorb and release greenhouse gases – it also plays a surprisingly great part in this exchange on land,” says Lise Lotte Sørensen, a senior researcher at Aarhus University’s Arctic Research Centre.

Sørensen and her colleagues have spent years on studying the exchange of greenhouse gases between the atmosphere, the sea ice and the sea beneath. In recent years, they have also taken an interest in what research groups focusing on the land areas have found. This curiosity prompted them to review the scientific literature to see to the extent of the interplay between these areas. ...

Although not much is known about the interaction between land and sea, scientists are starting to understand which mechanisms control the processes at sea. By studying sea ice in the wild and in an ice tank at the University of Manitoba in Canada, Sørensen and her colleagues found that there is an exchange of greenhouse gases between land and the atmosphere even when there is sea ice. When the ice temperature exceeds minus five degrees Celsius, channels start to emerge in the ice. These channels act as a link between the sea and the atmosphere.

The heated ice is not as passive as previously thought. It houses a great deal of chemical processes that cause the ice to release its own greenhouse gas contents, which then rain down into the sea. This transport of greenhouse gases may potentially have a great impact on the climate. “We now need to focus on this increased importance of the sea ice, and we need to carry out more studies of sea ice. Nobody has so far been aware that the sea ice has such a great impact on the climate and the exchange of greenhouse gases in the entire Arctic region,” says the researcher.


Posted by Amanda Graham – 19 February 2013; 6:27:11 PM – Permalink  

1,500-year cycle found in Arctic atmospheric pattern

(National Science Foundation via Epoch Times, 17 December 2012) -- A team of scientists supported by the National Science Foundation (NSF) has identified for the first time a clear 1,500-year cycle in the far North’s surface atmosphere pressure pattern. Called the Arctic Oscillation (AO), the cycle greatly influences weather in the Northern Hemisphere. The findings were published 11 November 2012 on Nature Geoscience’s website. Darby coauthored the paper with a team of scientists from Old Dominion and Kent State universities and the University of Southern California (USC). Coauthors are Joseph Ortiz, a geological oceanographer from Kent State; Chester Grosch, a physical oceanographer and computer scientist from ODU and Steven Lund, a geophysicist from USC.

William Wiseman, a program director in the Arctic Natural Sciences Program in NSF’s Office of Polar Programs, said the new research is innovative in its approach to separating human influences on climate from naturally occurring events. ... Working from a 20-meter-long sediment core raised offshore of Alaska from waters 1,300 meters deep, the researchers could detect varying amounts of iron-rich sand grains ice-rafted from Russia over the last 8,000 years. The core was originally recovered from the flank of Barrow Canyon by an NSF-funded oceanographic cruise....

Darby said that time-series analysis of the researchers’ geochemical record reveals a 1,500-year cycle that is similar to what other researchers have proposed in recent decades, based on scattered findings in paleoclimate records. But he and his colleagues are the first to find a high-resolution indicator of the Arctic record that resolves multidecadal-through-millennial-scale AO cycles, he said.

“Our record is the longest record to date to reconstruct the AO and documents that there is millennial scale variability in the AO,” Ortiz said. “The sedimentation rate at our site is also sufficient to statistically differentiate between a 1,000-year cycle and a 1,500-year cycle, which helps us to understand the dynamics of the response of the climate system to external forcing during the Holocene geological period.”

The 1,500-year cycle is distinct from a 1,000-year cycle found in a similarly analyzed record of total solar irradiance, the authors write, suggesting that the longer cycle arises from either internal oscillation of the climate system or as an indirect response to low-latitude solar forcing.


Posted by Amanda Graham – 11 January 2013; 11:41:29 AM – Permalink  

Ivory gulls threatened by eggshell thinning

(Unni Eikeseth, Norwegian Broadcasting Corporation via ScienceNordic, 20 December 2012) -- High levels of environmental contaminants are linked with thinner eggshells in the ivory gull, a red-listed high Arctic seabird. Scientists are concerned that pollutants and the stress from global warming could cause populations to plummet. The ivory gull (Pagophila eburnea) is a high Arctic seabird that lives year-round in an icy habitat. There are only about 8,000 -11,500 breeding pairs, and populations of this red-listed species have declined significantly in the last 20 years.

Norwegian and Russian scientists have found that the gull’s eggs are now 17 percent thinner than in samples collected before 1930, according to the December issue of the Norwegian University of Science and Technology (NTNU)’s magazine, Gemini. The researchers' findings have recently been published in the academic journal Science of the Total Environment. The ivory gull studies were conducted by the Norwegian Polar Institute in collaboration with NTNU and Russian research groups.


Posted by Amanda Graham – 4 January 2013; 5:25:52 PM – Permalink  

Bering Sea study finds prey density more important to predators than biomass

(Oregon State University press release via Phys.org, 3 January 2013) -- Marine resource managers often gauge the health of species based on overall biomass, but a new study of predator-prey relationships in the Bering Sea found that it isn't the total number of individuals that predators care about – it's how densely they are aggregated.

It's more than searching for an easy meal, the researchers say. Predators need to balance how much energy they expend in searching for food with the caloric and nutrient value of that which they consume. When prey doesn't aggregate, however, the search for food becomes much more difficult – affecting the health of the predators' offspring and the vitality of their overall population. Results of the study were published this week in the journal PLOS ONE. The study was part of the Bering Sea Integrated Ecosystem Research Project, which was funded by the North Pacific Research Board and the National Science Foundation.

"We had to think very differently about these interactions, trying to see the world from the predators' point of view," said Kelly Benoit-Bird, an Oregon State University marine ecologist and lead author on the study. "When we first tried to identify good foraging locations for predator species we looked at areas of high prey numbers because it makes sense that they'd be where the food is. But the results didn't match what we might have expected.


Posted by Amanda Graham – 3 January 2013; 4:14:40 PM – Permalink  

Ancient Antarctic treasure trove discovered

(Phys.org, 27 December 2012) -- The chance discovery of a 100 million year old fossil forest on an island east of New Zealand has unlocked new insights on ancient life close to the South Pole. Large trees in their original living position, early flowering plants, seed cones and rare insects preserved in a rock formation were discovered by researchers in the Chatham Islands.

The find reveals what is believed to be the first records of life close to the South Pole during the Cretaceous period, a time of extreme greenhouse conditions 145-65 million years ago. Led by palaeontologist Associate Professor Jeffrey Stilwell and palaeobotanist Dr Chris Mays from Monash University's School of Geosciences, a research team including Professor David Cantrill from the Royal Botanic Gardens Melbourne made the discovery. Associate Professor Stilwell said the fossils painted a picture of the formerly unknown life of the Cretaceous period when many southern continents including New Zealand and the Chatham Islands (Zealandia), Australia, Antarctica and South America were still mostly joined together as part of the southern landmass Gondwana.

"One hundred million years ago, the Earth was in the grip of a greenhouse effect – a planet of extreme heat with minimal ice (except in the high altitudes) and sea levels of up to 200 metres higher than today," Associate Professor Stilwell said. "Rainforests inhabited by dinosaurs existed in sub-polar latitudes and polar ecosystems were adapted to long months of winter darkness and summer daylight.


Posted by Amanda Graham – 3 January 2013; 1:34:51 PM – Permalink  

Great Arctic cyclone in summer was 'unprecedented:' study

(Michael D. Lemonick/Climate Central, 27 December 2012) -- It’s known as the Great Arctic Cyclone, and when it roared out of Siberia last August, storm watchers knew it was unusual. Hurricane-like storms are very common in the Arctic, but the most powerful of them (which are still far less powerful than tropical hurricanes) tend to come in winter. It wasn’t clear at the time, however, whether the August storm was truly unprecedented.

Now it is. A study published in Geophysical Research Letters looks at no fewer than 19,625 Arctic storms and concludes that in terms of size, duration and several other of what the authors call “key cyclone properties,” the Great Cyclone was the most extreme summer storm, and the 13th most powerful storm -- summer or winter -- since modern satellite observations began in 1979.

Although it came during a season when Arctic sea ice was plunging toward its lowest levels on record, the authors couldn’t establish that the unusually large areas of open ocean contributed to the storm’s intensity. On the flip side, they do argue that the storm contributed significantly to the breakup of the ice, and ultimately, to the record-low minimum extent of sea ice covering the Arctic. There’s at least circumstantial evidence to support this assertion: the rate of ice loss across the Arctic Ocean in August was unusually rapid, and it’s plausible to think that the churning action of the Great Cyclone helped fragment the already thin ice, letting it melt or disperse more easily.


Posted by Amanda Graham – 3 January 2013; 1:31:31 PM – Permalink  

Greenland's viking settlers gorged on seals

(University of Copenhagen press release, 19 November 2012) -- "Our analysis shows that the Norse in Greenland ate lots of food from the sea, especially seals," says Jan Heinemeier, Institute of Physics and Astronomy, Aarhus University. "Even though the Norse are traditionally thought of as farmers, they adapted quickly to the Arctic environment and the unique hunting opportunities. During the period they were in Greenland, the Norse ate gradually more seals. By the 14th century, seals made up between 50 and 80 per cent of their diet."

The Danish and Canadian researchers are studying the 80 Norse skeletons kept at the University of Copenhagen's Laboratory of Biological Anthropology in order to determine their dietary habits. From studying the ratio of the isotopes carbon-13 and carbon-15, the researchers determined that a large proportion of the Greenlandic Norse diet came from the sea, particularly from seals. ...

"Nothing suggests that the Norse disappeared as a result of a natural disaster. If anything they might have become bored with eating seals out on the edge of the world. The skeletal evidence shows signs that they slowly left Greenland. For example, young women are underrepresented in the graves in the period toward the end of the Norse settlement. This indicates that the young in particular were leaving Greenland, and when the numbers of fertile women drops, the population cannot support itself," Lynnerup explains. The findings challenge the prevailing view of the Norse as farmers that would have stubbornly stuck to agriculture until they lost the battle with Greenland's environment. These new results shake-up the traditional view of the Norse as farmers and have given archaeologists reason to rethink those theories.


Posted by Amanda Graham – 19 November 2012; 3:06:17 PM – Permalink  

Little Ice Age led to migration of island hopping arctic foxes

(Durham University press release, 11 September 2012) -- The Little Ice Age allowed a new wave of arctic foxes to colonise Iceland, according to new research. A "bridge" of sea ice appeared during a dip in temperatures between 200 to 500 years ago allowing arctic foxes to migrate to Iceland from different Arctic regions including Russia, North America and Greenland.

The research, led by scientists at Durham University, UK, said their findings showed the importance of sea ice in creating and maintaining the genetic population of the arctic fox across the polar regions where the animal is found. The multi-disciplinary approach used for this project could also be used to track the migration of other animals found on remote islands, the researchers said. While Iceland's approximately 10,000 strong arctic fox population is not at risk, the researchers added that increasing isolation from the rest of the Arctic, caused by warmer temperatures and a lack of sea ice, could further differentiate the island's population from their mainland relatives.

Ancient arctic foxes also crossed sea ice during previous ice ages to reach Iceland well before human settlement in the 9th Century. Warmer temperatures then melted the sea ice and isolated the ancient foxes on the island before the Little Ice Age reconnected Iceland to the mainland. The Little Ice Age saw temperatures plummet in the 16th to 19th Centuries across large parts of Europe and North America in particular, and rivers such as the Thames were frequently frozen enough to support ice skating and winter festivals.

The researchers analysed DNA samples from ancient remains of Icelandic arctic foxes dating from two late 9th to 12th Century archaeological sites and compared the findings to DNA data from their modern successors. They found that the ancient foxes shared a single genetic signature, while the modern population possesses five unique signatures.

The researchers were able to rule out different explanations for the increase in the amount of variation of the ancient foxes, including geographic reasons and breeding between farmed and wild arctic foxes. The team concluded that the most likely explanation for the boom in genetic diversity among arctic foxes was migration across sea ice that formed during the Little Ice Age. The research, partly funded by the Natural Environment Research Council (NERC), is published in Proceedings of the Royal Society B - Biological Sciences.


Posted by Amanda Graham – 12 October 2012; 2:00:46 PM – Permalink  

Tree growth in the Swedish Sub-Arctic: Setting new records

(H. Hedenas, et al., 2011. Changes in tree growth..., Ambio 40: 672-82, via CO2Science, 9 May 2012) -- The authors write that "during the last 15 years, there has been an increasing focus on how climate change has and will affect the distribution and extent of ecosystems around the globe including alpine and Arctic areas (e.g., Callaghan et al., 2005)," and in this regard they report that "field studies and remote sensing have revealed a recent increase in altitude of the tree line (e.g., Kullman, 2002)," as well as "an extension and increased cover of mountain birch forest (Tommervik et al., 2009; Rundqvist et al., 2011)."

More specifically, they say that Tommervik et al. have determined that "tree biomass has doubled over a 43-year period, within an area of Finnmarksvidda, and Rundqvist et al., have observed an increased density and cover of mountain birch in the treeline over the last three decades, within an area near Abisko village."


Posted by Amanda Graham – 9 May 2012; 11:33:15 AM – Permalink  

Study finds surprising Arctic methane emission source

(NASA press release, 22 April 2012) -- The fragile and rapidly changing Arctic region is home to large reservoirs of methane, a potent greenhouse gas. As Earth's climate warms, the methane, frozen in reservoirs stored in Arctic tundra soils or marine sediments, is vulnerable to being released into the atmosphere, where it can add to global warming. Now a multi-institutional study by Eric Kort of NASA's Jet Propulsion Laboratory, Pasadena, Calif., has uncovered a surprising and potentially important new source of Arctic methane: the ocean itself.

Kort, a JPL postdoctoral scholar affiliated with the Keck Institute of Space Studies at the California Institute of Technology in Pasadena, led the analysis while he was a student at Harvard University, Cambridge, Mass. The study was conducted as part of the HIAPER Pole-to-Pole Observations (HIPPO) airborne campaign, which flew a specially instrumented National Science Foundation (NSF)/National Center for Atmospheric Research (NCAR) Gulfstream V aircraft over the Pacific Ocean from nearly pole to pole, collecting atmospheric measurements from Earth's surface to an altitude of 8.7 miles (14 kilometers). The campaign, primarily funded by NSF with additional funding from NCAR, NASA and the National Oceanic and Atmospheric Administration, was designed to improve our understanding of where greenhouse gases are originating and being stored in the Earth system.

During five HIPPO flights over the Arctic from 2009 to 2010, Kort's team observed increased methane levels while flying at low altitudes over the remote Arctic Ocean, north of the Chukchi and Beaufort Seas. The methane level was about one-half percent larger than normal background levels. But where was the methane coming from? The team detected no carbon monoxide in the atmosphere that would point to possible contributions from human combustion activities. In addition, based on the time of year, location and nature of the emissions, it was extremely unlikely the methane was coming from high-latitude wetlands or geologic reservoirs. By comparing locations of the enhanced methane levels with airborne measurements of carbon monoxide, water vapor and ozone, they pinpointed a source: the ocean surface, through cracks in Arctic sea ice and areas of partial sea ice cover. The cracks expose open Arctic seawater, allowing the ocean to interact with the air, and methane in the surface waters to escape into the atmosphere. The team detected no enhanced methane levels when flying over areas of solid ice.


Posted by Amanda Graham – 7 May 2012; 5:28:05 PM – Permalink  

Analysis of speed of Greenland glaciers gives new insight for rising sea level

(NSF press release, 4 May 2012) -- Changes in the speed that ice travels in more than 200 outlet glaciers indicates that Greenland's contribution to rising sea level in the 21st century could be significantly less than the upper limits some scientists thought possible. The finding comes from a paper funded by the National Science Foundation (NSF) and NASA and published in today's journal Science. While the study indicates that a melting Greenland's contributions to rising sea levels could be less than expected, researchers concede that more work needs to be done before any definitive trend can be identified. Studies like this one are designed to examine more closely and in greater detail what is actually happening with the ice sheets, often using newer and more precise tools and thereby better defining the parameters that scientists use to make predictions, such as the upper limits of sea-level rise.

"This study provides more evidence that the rate at which these glaciers can dump ice into the ocean is indeed limited," said Ian Howat, assistant professor of Earth sciences and member of the Byrd Polar Research Center at Ohio State University, a co-author on the paper. "What remains to be seen is how long the acceleration will continue--but it appears that our worst-case scenarios aren't likely." The fate of the Earth's ice sheets and their potential contributions to sea-level rise as the globe warms are among the major scientific uncertainties cited in the Fourth Assessment of the Intergovernmental Panel on Climate Change (IPCC). This is in part because the Greenland and Antarctic ice sheets have historically been, and in large measure continue to be, relatively sparsely monitored, as compared to other parts of the globe. The faster the glaciers move, the more ice and melt water they release into the ocean. ...

"This study is a great example of the power of high-resolution data sets in both space and time, and the importance of looking carefully at as much data as possible in helping make the best predictions we can of future changes", said Henrietta Edmonds, program director for Arctic Natural Sciences in NSF's Office of Polar Programs. The scientists saw no clear indication in the new research that the glaciers will stop gaining speed during the rest of the century, and so by 2100 they could reach or exceed the scenario in which they contribute four inches to sea level rise.


Posted by Amanda Graham – 4 May 2012; 1:27:09 PM – Permalink  

New study chronicles the rise of agriculture in Europe

(American Association for the Advancement of Science press release via EurekAlert!, 26 April 2012) -- An analysis of 5,000-year-old DNA taken from the Stone Age remains of four humans excavated in Sweden is helping researchers understand how agriculture spread throughout Europe long ago. According to Pontus Skoglund from Uppsala University in Sweden and colleagues, the practice of farming appears to have moved with migrants from southern to northern Europe. Agricultural know-how wasn't the only thing that early European farmers introduced to the region. Based on their genetic data, Skoglund and the researchers say that Europe's first farmers eventually mixed their genes with the hunter-gatherers who lived there—a relationship that set the stage for today's modern European genome.

"We analyzed genetic data from two different cultures—one of hunter-gatherers and one of farmers—that existed around the same time, less than 400 kilometers (249 miles) away from each other," said Skoglund. "After comparing our data to modern human populations in Europe, we found that the Stone Age hunter-gatherers were outside the genetic variation of modern populations but most similar to Finnish individuals, and that the farmer we analyzed closely matched Mediterranean populations." These findings likely have something to do with the expansion of farming across Europe, according to the researchers. "When you put these findings in archaeological context, a picture begins to emerge of Stone Age farmers migrating from south to north across Europe," said Skoglund. "And the result of this migration, 5,000 years later, looks like a mixture of these two groups in the modern population." The researchers report their data in the 27 April issue of the journal Science, which is published by AAAS, the nonprofit international science society.

Most experts agree that the agricultural way of life originated about 11,000 years ago in the Near East before it reached the European continent some 5,000 years later. But this new study should help scientists understand the impact of that agricultural revolution on human diversity. Skoglund and his colleagues performed their analysis with the ancient remains of three hunter-gatherers who were associated with the Pitted Ware Culture and excavated from the island of Gotland, Sweden, along with those of a farmer, who was associated with the Funnel Beaker Culture and excavated from Gökhem parish, Sweden. "We know that the hunter-gatherer remains were buried in flat-bed grave sites, in stark contrast to the megalithic sites that the farmers built," said Mattias Jakobsson, a senior author of the Science report, also from Uppsala University. "The farmer we analyzed was buried under such a megalith, and that's just one difference that helps distinguish the two cultures."

Ancient hunter-gatherers had a distinct genetic signature that was similar to that of today's northern Europeans, while the farmer's genetic signature closely resembles that of southern Europeans, according to the researchers. Interestingly, these ancient genomes don't share many similarities with modern-day Swedes, despite their discovery and excavations in Sweden. "The fact that the hunter-gatherers are most similar to Finns, Orcadians and other extreme-northern populations suggests that they were indeed the last major part of the Mesolithic meta-population that populated large parts of Europe before the early farmers appeared," said Anders Götherström of Uppsala University, who is another senior author of the Science report. "And the fact that the farmer is most similar to southeastern Europeans makes sense too, as that is from where the spread of agriculture north and eastward started." "The results suggest that agriculture spread across Europe in concert with a migration of people," added Skoglund. "If farming had spread solely as a cultural process, we would not expect to see a farmer in the north with such genetic affinity to southern populations."


Posted by Amanda Graham – 4 May 2012; 1:13:55 PM – Permalink  

Duck-billed dinosaurs endured long, dark polar winters

(University of Cape Town, Museum of Nature and Temple University press release, 11 April 2012) -- Duck-billed dinosaurs that lived within Arctic latitudes approximately 70 million years ago likely endured long, dark polar winters instead of migrating to more southern latitudes, a recent study by researchers from the University of Cape Town, Museum of Nature and Science in Dallas and Temple University has found.

The researchers published their findings, "Hadrosaurs Were Perennial Polar Residents," in the April issue of the journal The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology. Anthony Fiorillo, a paleontologist at the Museum of Nature and Science, excavated Cretaceous Period fossils along Alaska's North Slope. Most of the bones belonged to Edmontosaurus, a duck-billed herbivore, but some others such as the horned dinosaur Pachyrhinosaurus were also found.

Fiorillo hypothesized that the microscopic structures of the dinosaurs' bones could show how they lived in polar regions. He enlisted the help of Allison Tumarkin-Deratzian, an assistant professor of earth and environmental science, who had both expertise and the facilities to create and analyze thin layers of the dinosaurs' bone microstructure. Another researcher, Anusuya Chinsamy-Turan, a professor of zoology at the University of Cape Town, was independently pursuing the same analysis of Alaskan Edmontosaurus fossils. ...

What the researchers found was bands of fast growth and slower growth that seemed to indicate a pattern. "What we found was that periodically, throughout their life, these dinosaurs were switching how fast they were growing," said Tumarkin-Deratzian. "We interpreted this as potentially a seasonal pattern because we know in modern animals these types of shifts can be induced by changes in nutrition. But that shift is often driven by changes in seasonality."


Posted by Amanda Graham – 12 April 2012; 11:15:09 PM – Permalink  

Three cheers for polar bears: New study shows population higher than thought

(Mark Johnson/newsnet5.com, 8 April 2012) -- CLEVELAND - Residents in the far northern territory of Nunavut in Canada have always disputed the scientific claims that the polar bear population in the cold, arctic region was in a death spiral. Back in 2004, American and Canadian scientists claimed that the polar bear numbers had dropped a whopping 22 percent and would continue to decline over the coming years. So what did the government of this small Canadian Territory near Hudson Bay do? They counted the bears themselves. The results have seriously challenged the doomsday predictions that polar bear populations in the Arctic are in rapid decline due to global warming, climate change and climate disruption. The numbers don't lie.

The aerial survey, completed in 2010, counted 1,013 Polar Bears along the Western Shore of Hudson Bay. Why is this number significant? That's a full 66 percent higher than estimates by scientists. Nunavut Government officials said that number could be even higher. Researchers, on the other hand, have been forecasting a steady decline in bear numbers in this critical region. They predicted a population in this area of 610 bears, due to warming temperatures and melting arctic sea ice. Melting ice would, scientists claim, hurt a bear's ability to find food and cause many to die. The Nunavut region is considered particularly important. Polar Bear numbers in the Hudson Bay region are considered a good guide to other bear colonies in the Arctic region.

According to the survey results , "Polar Bear population assessment in North America has historically relied on physical mark-recapture. These studies are logistically and financially intensive, and while widely accepted in the scientific community, local Inuit have voiced opposition to wildlife handling. To better reflect Inuit values and provide a rapid tool for monitoring Polar Bear population size, we developed and implemented an aerial survey in the Foxe Basin subpopulation (FB) during late summer, 2009 and 2010." The study shows that “the bear population is not in crisis as people believed,” said Drikus Gissing, Nunavut’s director of wildlife management. “There is no doom and gloom.” Since the survey was sponsored by the Nunavut government, it only covered the coastal areas in that territory, and did not cover the coastal areas in NW Quebec. So the numbers could be even higher.


Posted by Amanda Graham – 9 April 2012; 10:06:51 PM – Permalink  

Polar widows

(University of Tromsø via ScienceNordic, 23 March 2012) -- Being a polar explorer was extremely hard work, but it was certainly no bed of roses too for the explorer's wife. Sometimes it could take several years before she saw her husband again. "In the middle of March, I went ashore in Tromsø to be home for a fortnight. At home, there had come a little son. Then I had to say goodbye to my boy and wife, and head out on a journey that was planned to last for two to three years, but that would last for nearly four years."

With these words, Helmer Julius Hanssen described his "family life" with his wife Kristine Augusta before heading out on an expedition to the Northwest Passage in 1903. He accompanied the Norwegian polar explorer Roald Amundsen through both the Northwest and Northeast Passages, as well as on the famous South Pole expedition. But his life as an explorer had a downside, as he had to endure long periods without contact with his wife and children. "Based on what he says, you might think that Hanssen is without emotions, but I rather think he has developed some emotional distance from his family,” says Mary Anne Hauan, director of the University of Tromsø Museum. “Otherwise, his separation from his family would be too much to bear," she adds. We know more about what it was like for polar explorers on their expeditions, and their longing and loss, than we know about what it was like for their families to be without a husband and father for so long.

"Yes, and there were many who were gone for a long time,” says polar historian Harald Dag Jølle. He mentions Helmer Hanssen and Otto Sverdrup who went across the Arctic Ocean for three years (1893-1896) and then for another four years (1898-1902). ... Jølle says that polar explorers were paid wages, so from a financial perspective, their families managed well. “Otto Sverdrup renegotiated his wages when he got married. His wife Gretha had to depend on his income when he was travelling.” This was a time when many families had to survive long periods without a husband and father. According to Hauan, coastal women were accustomed to their men being absent, because of their work as traders and as fishermen. They were also well acquainted with the risks to which the men were exposed.


Posted by Amanda Graham – 7 April 2012; 1:36:44 PM – Permalink  

Declining sea ice to lead to cloudier Arctic: study

(AGU press release via Physorg.com, 31 March 2012) -- Arctic sea ice has been declining over the past several decades as global climate has warmed. In fact, sea ice has declined more quickly than many models predicted, indicating that climate models may not be correctly representing some processes controlling sea ice.

One source of uncertainty in models is feedback from cloud cover. Sea ice can affect cloud cover, as melting sea ice and increased evaporation from the ocean surface can lead to more cloud formation. In the Arctic, clouds have an overall warming effect on the surface, so greater cloudiness in this region could lead to even more sea-ice melt.

Liu et al., analyzed satellite observations of cloud cover and sea ice from 2000 to 2010 to evaluate feedbacks between sea ice and cloud cover. They find that a 1 percent decrease in sea ice concentration leads to a 0.36-0.47 percent increase in cloud cover, and that 22-34 percent of variance in cloud cover can be explained by changes in sea ice. So as sea ice declines, the researchers predict that the Arctic will become cloudier.

More information: A cloudier Arctic expected with diminishing sea ice, Geophysical Research Letters, doi:10.1029/2012GL051251 , 2012


Posted by Amanda Graham – 31 March 2012; 1:27:32 PM – Permalink  

Fossil of beluga ancestor found in Virginia

(CBC News, 30 March 2012) -- A three million-year-old skull found in the southern United States has traits of both beluga whales and narwhals, according to researchers. Nick Pyenson, curator of fossil marine mammals at the Smithsonian Institution, said the ancient ancestor of the two Arctic whale species appears to have once preferred warmer climates, as the fossils are found in temperate latitudes. Pyenson says it shows that Arctic species may have evolved some traits for reasons other than breaking through ice and snow. He also has some ideas about why the species went North.

“If your food moved north, you'd probably move north, too,” he said. “That is one possible suggestion as to why they evolved in Arctic and Subarctic ecosystems, is that they were following prey resources further north.” The skull was found in a mining pit in 1969 in Virginia but was only analyzed recently. The research appears in this month’s issue of the Journal of Vertebrate Paleontology.


Posted by Amanda Graham – 30 March 2012; 4:33:06 PM – Permalink  

Arctic sea ice may have passed crucial tipping point

(Fred Pearce/New Scientist, 27 March 2012) -- The disappearance of Arctic sea ice has crossed a "tipping point" that could soon make ice-free summers a regular feature across most of the Arctic Ocean, says a British climate scientist who is setting up an early warning system for dangerous climate tipping points.

Tim Lenton at the University of Exeter has carried out a day-by-day assessment of Arctic ice-cover data collected since satellite observation began in 1979. He presented his hotly anticipated findings for the first time at the Planet Under Pressure conference in London on Monday.

Up until 2007, sea ice systematically fluctuated between extensive cover in winter and lower cover in summer. But since then, says Lenton, the difference between winter and summer ice cover has been a million square kilometres greater than it was before, as a result of unprecedented summer melting. These observations are in contrast to what models predict should have happened.


Posted by Amanda Graham – 27 March 2012; 11:22:55 PM – Permalink  

Lemmings’ loss is bounty for moss

(Bjørnar Kjensli/Science Nordic, 23 March 2012) -- A so-called lemming year tends to follow a cold and snowy winter. This is because the small rodents breed prodigiously beneath a good layer of insulating snow. When it melts they appear in numbers. Lemming years provide feasts for predators and many species wait until they can rely on this food supply before having their own offspring. But in barren areas of the far north and higher altitudes further south food for lemmings is pretty scanty.

When freezing weather returns in the autumn the lemmings perish even if they aren’t devoured by predators. This is where the black fruited stink mosses enter the scene. They belong to a moss family that has specialized in getting nutrients from carrrion and animal droppings. One member of the family, Tetraplodon, is called “lemming moss” in Norwegian.

“We who study mosses know that after a lemming year we can expect to find many more interesting lemming and carrion mosses,” says Tommy Prestø, who manages the rock garden and biological station at Kongsvoll, run by the Trondheim Science Museum. These mosses aren’t carnivorous, nor do they have any traps or sticky mechanisms that attract or attach to animals. The moss is of course sedentary plant and can’t search around for dead rodents. But it solves these challenges with the help of flies and other insects. Contrary to most other moss species, the black fruited stink moss doesn’t release spores into the wind. They’ve developed strong colours and scents that entice blowflies and other insects that are attracted to carcasses. “These moss species use flies in the same way catkins or pussy willows attract bumblebees in the spring –the flies move from one moss to another and contribute to the spreading of spores, also to new dead rodents,” says Prestø.


Posted by Amanda Graham – 24 March 2012; 9:57:17 PM – Permalink  

The Viking journey of mice and men

(BioMed Central press release EurekAlert! 18 March 2012) -- House mice (Mus musculus) happily live wherever there are humans. When populations of humans migrate the mice often travel with them. New research published in BioMed Central's open access journal BMC Evolutionary Biology has used evolutionary techniques on modern day and ancestral mouse mitochondrial DNA to show that the timeline of mouse colonization matches that of Viking invasion.

During the Viking age (late 8th to mid 10th century) Vikings from Norway established colonies across Scotland, the Scottish islands, Ireland, and Isle of Man. They also explored the north Atlantic, settling in the Faroe Islands, Iceland, Newfoundland and Greenland. While they intentionally took with them domestic animals such as horses, sheep, goats and chickens they also inadvertently carried pest species, including mice.

A multinational team of researchers from the UK, USA, Iceland, Denmark and Sweden used techniques designed to characterize genetic similarity, and hence the relatedness of one population, or one individual, with another, to determine a mouse colonization timeline. Modern samples of mouse DNA were collected and compared to ancient samples dating mostly from the 10th to the 12th century. Samples of house mouse DNA were collected from nine sites in Iceland, Narsaq in Greenland, and four sites near the Viking archaeological site, L'Anse aux Meadows, in Newfoundland. The ancient samples came from the Eastern and Western settlements in Greenland and four archaeological sites in Iceland.

Analysis of mouse mitochondrial DNA showed that house mice (M. m. domesticus) hitched a lift with the Vikings, in the early 10th century, into Iceland, either from Norway or the northern part of the British Isles. From Iceland the mice continued their journey on Viking ships to settlements in Greenland. However, while descendants of these stowaways can still be found in Iceland, the early colonizers in Greenland have become extinct and their role has been filled by interloping Danish mice (M. m. musculus) brought by a second wave of European human immigrants.


Posted by Amanda Graham – 19 March 2012; 10:48:55 PM – Permalink  

Melting Arctic causes snowier winters: study

(AFP via Vancouver Sun, 27 February 2012) -- WASHINGTON - Melting sea ice in the Arctic may be causing the snowier winters the northern hemisphere has experienced in the last two seasons, U.S. and Chinese researchers reported on Monday. The level of Arctic sea ice reached a new record low in 2007, said the study led by the Georgia Institute of Technology and published in the Proceedings of the National Academy of Sciences.

Meanwhile, above-average snowfall has blanketed large parts of the northern United States, northwestern and central Europe, and northern and central China. The northern hemisphere has recorded its second and third largest snow covers in documented history in the last two seasons, spanning the winters of 2009-2010 and 2010-2011.

Researchers believe the disappearing Arctic ice is sending more water vapor into the air, and is interfering with atmospheric currents and westerly winds that would typically have swept snowy weather northward. Instead, more cold air is descending into the middle and lower latitudes, "leading to increased heavy snowfall in Europe and the northeast and midwest regions of the United States," said Jiping Liu, a senior research scientist at Georgia Tech.


Posted by Amanda Graham – 27 February 2012; 11:47:42 PM – Permalink  

Global permafrost zones shown in high-res Google Earth images

University of Zurich press release, 21 February 2012) -- Thawing permafrost will have far-reaching ramifications for populated areas, infrastructure and ecosystems. A geographer from the University of Zurich reveals where it is important to confront the issue based on new permafrost maps -- the most precise global maps around. They depict the global distribution of permafrost in high-resolution images and are available on Google Earth.

Unstable cable-car and electricity pylons and rock fall – Alpine countries like Switzerland have already had first-hand experience of thawing permafrost as a result of climate change. If temperatures continue to rise, the problem will intensify in many places. Permafrost, namely rock or soil with a negative temperature for at least two years, occurs in the subsurface and therefore cannot be mapped directly. The existing maps are thus fraught with major uncertainties that have barely been studied or formulated. Furthermore, due to the different modeling methods used the maps are difficult to compare.

Now, however, glaciologist Stephan Gruber from the University of Zurich has modeled the global permafrost zones for the first time in high resolution and using a consistent method. In his study recently published in The Cryosphere, the scientist estimates the global permafrost regions at 22 million square kilometers – a sixth of the world's exposed land surface. With a grid resolution of one square kilometer, Gruber's maps are the most precise permafrost maps in the world.


Posted by Amanda Graham – 21 February 2012; 11:24:30 PM – Permalink  GlobalPermafrostZonationIndexMap.kmz

Dead for 32,000 years, an Arctic plant is revived

(Nicholas Wade/New York Times, 20 February 2012) -- Living plants have been generated from the fruit of a little arctic flower, the narrow-leafed campion, that died 32,000 years ago, a team of Russian scientists reports. The fruit was stored by an arctic ground squirrel in its burrow on the tundra of northeastern Siberia and lay permanently frozen until excavated by scientists a few years ago. This would be the oldest plant by far that has ever been grown from ancient tissue. The present record is held by a date palm grown from a seed some 2,000 years old that was recovered from the ancient fortress of Masada in Israel.

The new report is by a team led by Svetlana Yashina and David Gilichinsky of the Russian Academy of Sciences research center at Pushchino, near Moscow, and appears in Tuesday’s issue of The Proceedings of the National Academy of Sciences of the United States of America. “This is an amazing breakthrough,” said Grant Zazula of the Yukon Paleontology Program at Whitehorse in Yukon Territory, Canada. “I have no doubt in my mind that this is a legitimate claim.” It was Dr. Zazula who showed that the apparently ancient lupine seeds found by the Yukon gold miner were in fact modern. ...

The Russian researchers excavated ancient squirrel burrows exposed on the bank of the lower Kolyma River, an area thronged with mammoth and woolly rhinoceroses during the last ice age. Soon after being dug, the burrows were sealed with windblown earth, buried under 125 feet of sediment and permanently frozen at minus 7 degrees Celsius. Some of the storage chambers in the burrows contain more than 600,000 seeds and fruits. Many are from a species that most closely resembles a plant found today, the narrow-leafed campion (Silene stenophylla).

Working with a burrow from the site called Duvanny Yar, the Russian researchers tried to germinate the campion seeds, but failed. They then took cells from the placenta, the organ in the fruit that produces the seeds. They thawed out the cells and grew them in culture dishes into whole plants. ... They grew 36 ancient plants, which appeared identical to the present day narrow-leafed campion until they flowered, when they produced narrower and more splayed-out petals. ... The Russian team says it obtained a radiocarbon date of 31,800 years from seeds attached to the same placenta from which the living plants were propagated. ...

Eske Willerslev, an expert on ancient DNA at the University of Copenhagen, said the finding was “plausible in principle,” given the conditions in permafrost. But the claim depends on the radiocarbon date being correct: “It’s all resting on that — if there’s something wrong there it can all fall part.” ...


Posted by Amanda Graham – 20 February 2012; 8:38:40 PM – Permalink  

Volcanic activity behind Little Ice Age

(Randy Boswell/Vancouver Sun, 31 January 2012) -- Melting icefields on Baffin Island, one of the clearest signs of climate change on Earth, have yielded the strongest evidence yet for the timing and cause of another major climate event from the planet's past: the so-called Little Ice Age, a sudden and mysterious cooling of the globe that began about 700 years ago. Recently exposed remains of plants that had been buried under Baffin Island ice for centuries provided the crucial clue that has led an international team of researchers to conclude the Little Ice Age was triggered by volcanic eruptions between 1275 and 1300 and was sustained by changes in Arctic sea-ice cover that lasted several centuries.

Writing in the latest issue of the journal Geophysical Research Letters, the team of 13 scientists from the U.S., Iceland and Britain notes that, "there is no clear consensus on the timing, duration, or controlling mechanisms" of the Little Ice Age, which has been attributed by some experts to the onset of a period of reduced heat from the sun. Without fully discounting the influence of the solar radiation cycle on the medieval cooling trend, the researchers found, however, clear indications on Baffin Island that mosses and other plants that had thrived in the centuries before AD 1300 were suddenly killed during a time marked by cataclysmic discharges from volcanoes erupting in the Southern Hemisphere.

A similar series of tropical volcanic eruptions around 1450, which initially blocked sunlight but also extended Arctic ice cover and increased ice-berg production in the North Atlantic, coincided with another pulse of ice-field growth and the flash-freeze killing of plants at different locations on the Nunavut island. Significantly, the authors note, the "entombed vegetation" found at sites along a 1,000-km stretch of Baffin Island has only become apparent in recent years as "rapidly melting ice caps" in Arctic Canada began to reveal plant material unseen since the Middle Ages.


Posted by Amanda Graham – 15 February 2012; 11:35:07 AM – Permalink  

Yellow-cedar are dying in Alaska: Scientists now know why

(Science Daily, 1 February 2012) -- Yellow-cedar, a culturally and economically valuable tree in southeastern Alaska and adjacent parts of British Columbia, has been dying off across large expanses of these areas for the past 100 years. But no one could say why -- until now.

"The cause of tree death, called yellow-cedar decline, is now known to be a form of root freezing that occurs during cold weather in late winter and early spring, but only when snow is not present on the ground," explains Pacific Northwest Research Station scientist Paul Hennon, co-lead of a synthesis paper recently published in the February issue of the journal BioScience. "When present, snow protects the fine, shallow roots from extreme soil temperatures. The shallow rooting of yellow-cedar, early spring growth, and its unique vulnerability to freezing injury also contribute to this problem."

Yellow-cedar decline affects about 60 to 70 percent of trees in forests covering 600,000 acres in Alaska and British Columbia. The paper, "Shifting Climate, Altered Niche, and a Dynamic Conservation Strategy for Yellow-Cedar in the North Pacific Coastal Rainforest," summarizes 30 years of research and offers a framework for a conservation strategy for yellow-cedar in Alaska.


Posted by Amanda Graham – 2 February 2012; 12:06:41 PM – Permalink  

Polar Research article explores use of community engagement in IPY television series

(Catherine L. Carry, Kath Clarida, Denise Rideout, Dianne Kinnon, Rhonda M. Johnson/Polar Research, 31 January 2012) -- The three-part television broadcast Qanuqtuurniq – finding the balance was an International Polar Year communications and outreach project concerning Inuit health and wellness. The goal of this project was to engage the Inuit public and others in ‘‘real-time’’ dialogue about health and wellness issues and health research, and to deliver key messages. It was aired live in the Inuit language (with English captions/sub-titles) from Iqaluit, Nunavut, Canada, in May 2009 and simultaneously webcast. Qanuqtuurniq – finding the balance used an Inuit communications model for remote communities that was developed in the Arctic in 1994 by the Inuit Broadcasting Corporation/Inuit Communications.

... more than 250 people were engaged through the use of a diverse range of methods, including content working groups, stakeholder input, music recordings, pre-recorded community programme videos, live and public screening of the broadcasts, live panels, live audiences, public phone-ins, Skype video-conferencing and real-time online chat, focus groups and e-mail. This article examines the project in light of the principles of ‘‘community engagement’’, demonstrating that Qanuqtuurniq – finding the balance exemplifies community engagement in a number of significant ways, including heavily involving community members in the selection of the health theme content of the televised programmes and through the formation of focus groups.


Posted by Amanda Graham – 2 February 2012; 12:03:24 PM – Permalink  

What do killer whales eat in the Arctic?

(BioMed Central press release, 29 January 2012) -- Killer whales (Orcinus orca) are the top marine predator, wherever they are found, and seem to eat everything from schools of small fish to large baleen whales, over twice their own size. The increase in hunting territories available to killer whales in the Arctic due to climate change and melting sea ice could seriously affect the marine ecosystem balance. New research published in BioMed Central's re-launched open access journal Aquatic Biosystems has combined scientific observations with Canadian Inuit traditional knowledge to determine killer whale behaviour and diet in the Arctic. Orca have been studied extensively in the northeast Pacific ocean, where resident killer whales eat fish, but migrating whales eat marine mammals. Five separate ecotypes in the Antarctic have been identified, each preferring a different type of food, and similar patterns have been found in the Atlantic, tropical Pacific, and Indian oceans. However, little is known about Arctic killer whale prey preference or behaviour.

Traditional Ecological Knowledge (TEK) is increasingly being used to supplement scientific observations. Researchers from Manitoba visited 11 Canadian Nunavut Inuit communities and collated information from over 100 interviews with hunters and elders. The Inuit reported that killer whales would 'eat whatever they can catch', mainly other marine mammals including seals (ringed, harp, bearded, and hooded) and whales (narwhal, beluga and bowhead). However there was no indication that Arctic killer whales ate fish. Only seven of the interviewees suggested that killer whales ate fish, but none of them had ever seen it themselves.


Posted by Amanda Graham – 30 January 2012; 12:33:28 AM – Permalink  

Airborne geophysical survey offers new insight into permafrost in Alaska

(U.S. Department of the Interior, U.S. Geological Survey press release, 23 January 2012) -- Denver, CO - A pioneering airborne electromagnetic survey in the Yukon Flats near Fort Yukon, Alaska, by the U.S. Geological Survey has yielded unprecedented images of the presence and absence of permafrost to depths of roughly 328 feet. The airborne survey captured images of permafrost over a substantially larger area, and with greater data density, than has been previously achieved using sparse boreholes and ground-based geophysics.

"Liquid water conducts electricity better than ice," explained USGS director Marcia McNutt. "We can detect from the air the weak magnetic fields generated by those electric currents, thus distinguishing quickly and easily melted from frozen ground. This new technology, and the maps of changing permafrost, will be valuable for both climate change research and engineering in the challenging Alaskan environment." Because the Yukon Flats is near the boundary between continuous permafrost to the north and discontinuous permafrost to the south, it is an important place to study permafrost dynamics.

Dr. Burke Minsley, geophysicist in the USGS’ Crustal Geophysics and Geochemistry Science Center in Denver and lead author of the study in Geophysical Research Letters, and his team surveyed more than 116 square miles centered 140 miles northeast of Fairbanks. Their data not only capture in detail the distribution of permafrost and its relation to surface- and groundwater features, but also the legacy of the Yukon River lateral migration over a period of roughly 1,000 years as manifested as a thawed region of permafrost.

Knowledge of the current permafrost distribution is critical for analyses designed to evaluate hydrologic and ecologic consequences of climate warming. It also provides a baseline for future investigation of the dynamic evolution of permafrost systems. In addition, the study is important because it presents a methodology for assessing permafrost not only in Alaska but throughout sub-Arctic and Arctic regions.


Posted by Amanda Graham – 30 January 2012; 12:29:58 AM – Permalink  

Alaskan lake bed cores show expanding Arctic shrubs may slow erosion

(American Geophysical Union press release via Physorg.com, 31 December 2012) -- The relationship between permafrost, Arctic vegetation, soil erosion, and changing air temperatures is complicated at best. For instance, rising temperatures melt surface permafrost layers and increase shrub growth. These shrubs can catch drifting snow, insulating the soil during the winter, and accelerate permafrost degradation—facilitating their own proliferation. Alternatively, increased vegetation can shift energy transfer dynamics, cooling the surface and protecting permafrost. Hence, expanding Arctic shrub populations may either reinforce or counteract permafrost erosion. The complexity of the interactions makes firsthand accounts of these dynamics particularly important.

To figure out how the permafrost ecosystem has evolved under modern warming for the northernmost reaches of Alaska, Tape et al. pulled observations from a diverse set of sources. The authors took sediment cores from lake beds in the study area to determine changes in sedimentation rates, and hence watershed erosion, for the past 60–100 years. Tree ring analyses indicate the changing growth rates of tall shrubs, and satellite observations show changes in shrub extent. The authors find that erosion rates were increasing or fluctuating prior to 1980, after which they declined for three of the four lakes under investigation. The authors suggest that this reduction in erosion rate was driven by the observed 18 percent increase in the coverage of tall shrub, whose roots could have helped stabilize the soil. The authors suggest that their technique, of using lake bed soil cores to detect permafrost degradation at the watershed scale, will be particularly important for furthering the understanding of the changing Arctic.

More information: "Twentieth century erosion in Arctic Alaska foothills: The influence of shrubs, runoff, and permafrost," Journal of Geophysical Research-Biogeosciences, doi: 10.1029/2011JG001795 , 2011.


Posted by Amanda Graham – 7 January 2012; 5:56:42 PM – Permalink  

Russian river water unexpected culprit behind Arctic freshening - with video

(Sandra Hines/UW Today, 4 January 2012) -- A hemisphere-wide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea. Frigid freshwater flowing into the Arctic Ocean from three of Russia’s mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the Jan. 5 issue of Nature.

The new findings show that a low pressure pattern created by the Arctic Oscillation from 2005 to 2008 drew Russian river water away from the Eurasian Basin, between Russia and Greenland, and into the Beaufort Sea, a part of the Canada Basin bordered by the United States and Canada. It was like adding 10 feet (3 meters) of freshwater over the central part of the Beaufort Sea.

“Knowing the pathways of freshwater in the upper ocean is important to understanding global climate because of freshwater’s role in protecting sea ice – it can help create a barrier between the ice and warmer ocean water below – and its role in global ocean circulation. Too much freshwater exiting the Arctic would inhibit the interplay of cold water from the poles and warm water from the tropics,” said Jamie Morison, an oceanographer with the University of Washington’s Applied Physics Laboratory and lead author of the Nature paper.

See JPL press release on this study.


Posted by Amanda Graham – 5 January 2012; 11:47:25 AM – Permalink  

How Arctic Alaska sea ice monitoring benefits scientists, industrialists

(Doug O'Harra/Alaska Dispatch, 2 January 2012) -- A Bering Sea swell rises 20 feet and compresses the seabed with tons of extra mass, sending a tiny seismic wave rippling through Earth. Heavy surf pounds a bedrock beach on Alaska’s west coast, and the Earth beyond rumbles with miniscule but detectable motion. The home planet is perpetually ahum with such ocean-generated microseismic waves. Well-placed sensors can record this low-power energy, allowing scientists to eavesdrop, in a sense, on the restless sea.

But what happens when the ocean starts to freeze and the growing pack ice dampens the size and power of swell and surf? Do ice floes change the signal — or simply shut it down? A new study in Geological Research Letters reports a dramatic correlation between the formation of Bering Sea ice and the power of this “microseismic signal,” suggesting that devices similar to earthquake sensors may someday be able to monitor sea ice strength. In some cases, these sensors may provide a more accurate picture than satellites, the authors concluded.

“Because strong sea ice prevents large ocean waves from forming, sea ice can therefore significantly affect microseism amplitudes,” wrote Victor Tsai of the California Institute of Technology and Daniel McNamara, with the U.S. Geologic Hazards Science Center in Colorado, in their report, Quantifying the influence of sea ice on ocean microseism using observations from the Bering Sea, Alaska. “This link between sea ice and microseism is not only a robust one but can be quantified.” The scientists discovered that 75 to 90 percent of the variability in the seismic energy generated by the Bering Sea could be explained by the spread, density and thickness of sea ice. Visualizing the immense mechanical power of the roiling sea is critical to understanding how this might work.


Posted by Amanda Graham – 4 January 2012; 2:15:25 PM – Permalink  

Increased ice loss resulted in greater Greenland bedrock lifting

(Ohio State University press release via redOrbit, 11 December 2011) -- A higher-than-normal 2010 melting season sped up the melting of ice in southern Greenland, causing sizable portions of the island’s bedrock to rise somewhere about a quarter of an inch more than usual, an Ohio State University (OSU) researcher said on Friday.

According to an OSU press release, Michael Bevis, Ohio Eminent Scholar in Geodynamics and professor in the OSU School of Earth Sciences, said that 50 GPS stations spread across the coast of Greenland normally “detect uplift of 15 mm (0.59 inches) or more, year after year. But a temperature spike in 2010 lifted the bedrock a detectably higher amount over a short five-month period – as high as 20 mm (0.79 inches) in some locations.”

Those comments came during a presentation by Bevis, who serves as the principal investigator for the Greenland GPS Network (GNET), at the American Geophysical Union (AGU) meeting in San Francisco. He also addressed what implication the findings could have in relation to climate change, saying that “pulses of extra melting and uplift imply that we’ll experience pulses of extra sea level rise… The process is not really a steady process.” In a December 9 article, UPI also said that the Bevis believes that uplift was the result of accelerated ice loss in the region, noting that the southern part of Greenland lost an extra 100 billion tons of ice due to the above average conditions.


Posted by Amanda Graham – 16 December 2011; 3:02:37 PM – Permalink  

Melting permafrost amplifies global warming effect

(University of Florida and University of Alaska Fairbanks press release via redOrbit, 1 December 2011) -- According to a survey published in the November 30 issue of the journal Nature, melting permafrost in the northern climes is releasing large amounts of methane and carbon, amplifying the global warming effect. When permafrost melts, long dormant microbes come alive and break down the organic matter underneath the layers of frozen soil creating methane. Methane gas has 2.5 times the effect on the atmosphere than carbon dioxide, creating a greater warming effect.

The survey, led by Edward Schuur from the University of Florida and graduate student Benjamin Abbott from the University of Alaska Fairbanks asked climate scientists what percentage of the permafrost will thaw, how much carbon will be emitted and how much of that carbon is methane. The researchers estimate by 2100 that the amount of carbon released from these largely untapped stores of carbon will be 1.7 to 5.2 times larger than recent modeling studies show.

According to Abbott, “The larger estimate is due to the inclusion of processes missing from current models and new estimates of the amount of organic carbon stored deep in frozen soils. There’s more organic carbon in northern soils than there is in all living things combined; it’s kind of mind boggling.” According to estimates there are 1,700 gigatons of organic carbon stored within the northern soils, four times more than all the carbon ever emitted by modern human activity and twice that currently being held in the atmosphere.


Posted by Amanda Graham – 2 December 2011; 3:53:33 PM – Permalink  

Ravens use gestures to signal potential partners

(Max Planck Institute for Ornithology and University of Vienna press release via redOrbit, 30 November 2011) -- Ravens use their beaks and wings to point and hold up objects in order to attract attention, much like humans use our hands to make gestures, according to a new study by German and Austrian experts. The study is the first time researchers have observed such gestures in the wild by animals other than primates, suggesting that ravens (Corvus corax) may be far more intelligent than previously believed.

Simone Pika from the Max Planck Institute for Ornithology and Thomas Bugnyar from the University of Vienna found that the ravens also use these so-called deictic gestures in order to test the interest of a potential partner, or to strengthen an already existing bond. Children frequently use distinct gestures — such as “pointing” (“look here”) and “holding up of objects” (“take this”) — to draw the attention of adults to external objects. This typically begins around the age of nine to twelve months, before children utter their first spoken words. Scientists believe these gestures are based on relatively complex intelligence abilities, and represent the starting point for the use of symbols and therefore also human language. As such, deictic gestures are seen as milestones in the development of human speech. ... Deictic gestures thus represent an extremely rare form of communication evolutionarily and have been suggested as confined to primates only. The current study, however, finds that such behavior is not restricted to humans and great apes.

Pika and Bugnyar spent two years investigating the non-vocal behavior of individually marked members of a wild raven community in the Cumberland Wildpark in Grünau, Austria. They observed that the ravens used their beaks to point to objects such as moss, stones and twigs. These distinct gestures were predominantly aimed at partners of the opposite sex, and resulted in frequent orientation of recipients to the object and the signallers. The ravens subsequently interacted with each other by, for example, billing or joint manipulation of the object. Pika said the study provided the first evidence that ravens use gestures “to test the interest of a potential partner or to strengthen an already existing bond”. ... The current study shows that differentiated gestures have particularly evolved in species with a high degree of collaborative abilities.

“Gesture studies have too long focused on communicative skills of primates only,” Pika said. “The mystery of the origins of human language, however, can only be solved if we look at the bigger picture and also consider the complexity of the communication systems of other animal groups.” The study was published November 29 in the journal Nature Communications. November 29, 2011.


Posted by Amanda Graham – 30 November 2011; 11:26:48 AM – Permalink  

New on-line journal of Nordic research

(Norden News, 16 November 2011) -- An English-language news service featuring research from the Nordic countries has just been launched. ScienceNordic will present daily news items to an international audience. The actual research has long been international and Nordic researchers work at global level, often in international networks. They also regularly co-publish along with colleagues from other countries and use English as the academic language.

"For some reason, publicity about Nordic research has been remarkably local though," explains Nina Kristiansen, editor of forskning.no and co-editor of ScienceNordic for the next two years. American and British media and institutions currently dominate the scene when it comes to spreading news and information about research. They have greater resources and a natural advantage in terms of language, so journalists all over the world write stories about American research findings. "The findings generated by Nordic research are equally good and equally newsworthy. There has been a knowledge gap in the market, and we aim to plug it," says Vibeke Hjortlund, editor of Videnskab.dk.

"ScienceNordic will prioritise disciplines in which the Nordic countries stand out or have a particularly positive record, e.g. alternative energy, the climate, the environment, oil, biotechnology, gender equality and the economics of the welfare state," Kristiansen adds. ScienceNordic covers all five Nordic countries, as well as Greenland, the Faroe Islands and Åland. Videnskab.dk and forskning.no have received seed funding for ScienceNordic from Nordforsk, the Norwegian Ministry of Education and Research and the Danish Ministry of Education. The web address is http://sciencenordic.com/


Posted by Amanda Graham – 16 November 2011; 10:43:49 PM – Permalink  

Global warming causes growth spurt in some Arctic forests

(Summit County Citizens Voice, 14 November 2011) -- SUMMIT COUNTY - Forests at the edge of Alaska’s tundra have put on a growth spurt in the past hundred years, and especially since about 1950, according to researchers with Columbia University’s LaMont-Doherty Earth Observatory.

The scientists recently completed a detailed tree-ring study dating back to 1067. The results suggest that at least some forests may be adapting the rapidly warming climate in the Arctic. Global temperatures have climbed about 1.6 degrees since the 1950s, but some parts of northern latitudes have climbed about 4 to 5 degrees during that same span.

“For the moment, warmer temperatures are helping the trees along the tundra,” said study coauthor Kevin Anchukaitis, a tree-ring scientist at Lamont. “It’s a fairly wet, fairly cool, site overall, so those longer growing seasons allow the trees to grow more.”

The study, published in the journal Environmental Research Letters, spans 1,000 years and bolsters the idea that far northern ecosystems may play a future role in the balance of planet-warming carbon dioxide that remains in the air. It also strengthens support for an alternative technique for teasing climate data from trees in the far north, sidestepping recent methodological objections from climate skeptics.


Posted by Amanda Graham – 14 November 2011; 3:41:14 PM – Permalink  

Ancient bronze artifact from East Asia unearthed at Alaska archaeology site

(University of Colorado at Boulder press release, 14 November 2011) -- A team of researchers led by the University of Colorado Boulder has discovered the first prehistoric bronze artifact made from a cast ever found in Alaska, a small, buckle-like object found in an ancient Eskimo dwelling and which likely originated in East Asia.

The artifact consists of two parts -- a rectangular bar, connected to an apparently broken circular ring, said CU-Boulder Research Associate John Hoffecker, who is leading the excavation project. The object, about 2 inches by 1 inch and less than 1 inch thick, was found in August by a team excavating a roughly 1,000-year-old house that had been dug into the side of a beach ridge by early Inupiat Eskimos at Cape Espenberg on the Seward Peninsula, which lies within the Bering Land Bridge National Preserve. Both sections of the artifact are beveled on one side and concave on the other side, indicating it was manufactured in a mold, said Hoffecker, a fellow at CU-Boulder's Institute of Arctic and Alpine Research. A small piece of leather found wrapped around the rectangular bar by the research team yielded a radiocarbon date of roughly A.D. 600, which does not necessarily indicate the age of the object, he said. "I was totally astonished," said Hoffecker.

"The object appears to be older than the house we were excavating by at least a few hundred years." Hoffecker and his CU-Boulder colleague Owen Mason said the bronze object resembles a belt buckle and may have been used as part of a harness or horse ornament prior to its arrival in Alaska. While they speculated the Inupiat Eskimos could have used the artifact as a clasp for human clothing or perhaps as part of a shaman's regalia, its function on both continents still remains a puzzle, they said.

Since bronze metallurgy from Alaska is unknown, the artifact likely was produced in East Asia and reflects long-distance trade from production centers in either Korea, China, Manchuria or southern Siberia, according to Mason. It conceivably could have been traded from the steppe region of southern Siberia, said Hoffecker, where people began casting bronze several thousand years ago. Alternatively, some of the earliest Inupiat Eskimos in northwest Alaska -- the direct ancestors of modern Eskimos thought to have migrated into Alaska from adjacent Siberia some 1,500 years ago -- might have brought the object with them from the other side of the Bering Strait. "It was possibly valuable enough so that people hung onto it for generations, passing it down through families," said Mason, an INSTAAR affiliate and co-investigator on the Cape Espenberg excavations.


Posted by Amanda Graham – 14 November 2011; 1:14:21 PM – Permalink  

Scientists discover new dinosaur on Alaska's North Slope

(Ned Rozell/Alaska Science Forum via Fairbanks Daily News-Miner, 13 November 2011) -- FAIRBANKS - There’s a new kind of dinosaur out there, and it lived in Alaska. Its bones, long turned to stone, are part of a cliff in northern Alaska. That’s where dinosaur-hunter Tony Fiorillo brushed dirt away from a portion of its massive skull, something that most of us would mistake for a rock.

The year was 2006. It was August and summer had fled the Colville River, if it had been there at all. Fiorillo, who visits Alaska each summer from Dallas, where he works at the Museum of Nature and Science, remembers climbing from his tent with a heavy head every morning. He later learned he was working with pneumonia. On one wet, miserable day, Fiorillo was clinging to a hillside above the river, spading the soil gently with a trowel. Noticing an unusual lump, he picked up a brush to gently whisk the dirt away. Suddenly, an entire skull came into focus, and he felt a warm flush of discovery. “When I had that moment of recognition, only (a large nasal bone) was exposed,” Fiorillo said. “But in my mind I could see the rest of the skull.” ...

Fiorillo and others didn’t know they had a new dinosaur for five years because it took that long to sort out all the dinosaur bones from a hunk of rock that flew by helicopter sling from the Colville River to a small airstrip, where a pilot flew it to Fairbanks. From there, it traveled down the Alaska Highway and all the way to Texas by truck. In Dallas, fossil preparer Ron Tykoski began the long task of chipping and carving apart the rock. He found the remains of many dinosaurs. ...

When he finished, the two paleontologists saw that several features on the skull were different enough from similar dinosaurs that no one had documented it until now. Fiorillo and Tykoski just unveiled the evidence for Pachyrhinosaurus perotorum at a paleontologist’s meeting in Las Vegas, reintroducing to the world an arctic dinosaur that once stomped through the ferns and forests of northern Alaska.


Posted by Amanda Graham – 13 November 2011; 11:02:30 AM – Permalink  

Nunavik's Leaf River caribou herd "decreasing," survey concludes

(Nunatsiaq News, 11 November 2011) -- The results of the 2011 population survey of Nunavik’s Leaf River caribou herd are in. The survey established the size of the herd at 430,000 caribou — give or take about 98,000 animals, Quebec’s minister of natural resources and wildlife, Serge Simard, announced Nov. 11.

Adult survival rate and the number of calves produced are low, said a government news release. That indicates that this herd is in “a decreasing phase,” confirming what biologists have said about the size and health of the herd. “Although the population of the LRH (Leaf River herd) is still relatively large, we must keep exercising care, since biological monitoring indicate(s) that the herd size is decreasing. It is therefore important to maintain very stringent management objectives,” Simard said.


Posted by Amanda Graham – 11 November 2011; 4:36:36 PM – Permalink  

Reindeer pant to release heat

(Journal of Experimental Biology press release, 28 October 2011) -- Their thick coats are the perfect protection in keeping the cold away from their bodies in the Arctic winters that they endure. But the researchers wondered how they keep cool when they are active and generating heat Arnoldus Blix, one of the authors of the study from the University of Tromsø, Norway, says that these animals have three tactics for staying cool.

The first cooling technique the reindeer use is panting with their mouths closed to evaporate water from the nose. Secondly they pant with their mouths open to evaporate water from the tongue. Finally when their body temperature finally rises to more dangerous levels, around 39 degrees C, they pant with their mouths open and activate an internal cooling system that diverts cooler blood from the front of the face directly to the brain. The reindeer were chosen for the study because of their domesticated nature.

According to Blix, “Reindeer are the best animals to work with; once they trust the trainer they will do anything for you.” The researchers trained the reindeer to run on a treadmill at 9 km/h in temperatures that ranged from 10 degrees C up to 30 degrees C. In the beginning of the run the reindeer had a breath rate of 7 breaths per minute and then the rate increased up to 260 breaths per minute. The high rate of breathing was so the inhaled chilly air and evaporated water from mucous membranes cooled the blood in the nasal sinuses before sending it back into the body through the jugular vein to keep their temperature down, according to Blix. Study findings were published in the Journal of Experimental Biology.


Posted by Amanda Graham – 31 October 2011; 12:29:53 AM – Permalink  

Arctic ice shelf might have broken up before

(Indo Asian News Service, 26 October 2011) -- London - Researchers think a Canadian ice shelf had broken up 1,400 years ago, long before industrialisation impacted the planet. A study of sedimentary material on the bottom of Disraeli Fjord in Canada turned up proof of what the team from Universite Laval in Canada described as a major fracturing event 1,400 years ago. They believe at least an ice shelf, Ward Hunt north of Ellesmere Island, Nunavut, Canada, the largest remaining ice shelf in the Arctic at 170 square miles, broke up and then re-froze 800 years ago, the journal Proceedings of the National Academy of Sciences reports.

Ice shelves are thick ice crusts which have been pushed out to sea by the pressure from glaciers. They act as dams in fjords and result in sediment building up at the boundary between fresh water from the ice and salt water from the ocean, according to the Daily Mail. Researchers used carbon dating and other techniques to examine the sediment and were able to create a timeline of events.


Posted by Amanda Graham – 26 October 2011; 12:00:15 PM – Permalink  

Hunters arrived in North America earlier than previously thought

(Texas A&M University press release and other sources via redOrbit, 21 October 2011) -- A team of researchers, led by a Texas A&M archaeologist, has used a bone point fragment from an ancient mastodon rib to confirm that hunters roamed North America at least 800 years earlier than previously thought, the university said in a Thursday press release. By studying the tip of that fragment, which was found in a mastodon rib from a Washington-based archeological dig, Michael Waters, director of the Center for the Study of the First Americans in the Department of Anthropology at Texas A&M, and his colleagues believe that it proves that humans were present there about 13,800 years ago. That would mean hunters were here some 800 years before the Clovis people.

According to the university, an adult male mastodon was excavated from a pond at a site near Manis, Washington, back in the late 1970s. Broken bones on the creature suggested that it had been killed or butchered by human hunters, Waters said in the media release, but they were unable to recover any stone tools or weapons at the location.

“Waters contacted team member and original excavator, Carl Gustafson, about performing new tests on the rib with the bone point,” the Texas A&M press release said. “New radiocarbon dates confirmed that the site was 13,800 years old. High resolution CT scanning and three-dimensional modeling confirmed that the embedded bone was a spear point, and DNA and bone protein analysis showed that the bone point was made of mastodon bone.”

Sindya N. Bhanoo of the New York Times adds that the CT scanning confirmed that the bone point, embedded within the rib, was a hunting tool that was over 10 inches long and sharpened. Waters and his associates published their findings in the journal Science. Gustafson, an archeologist from Washington State University, reportedly was convinced that humans had hunted and killed the animal, at least partially for food, Eric Berger of the Houston Chronicle reported on Thursday. Few people in his profession believed that humans could have been present in North America long enough ago to have been able to have done the deed.


Posted by Amanda Graham – 21 October 2011; 2:55:14 PM – Permalink  

Arctic ozone loss 'unprecedented,' scientists say

CBC News, 2 October 2011) -- Unusual winter weather in the atmosphere high above the Earth's surface caused an "unprecedented" loss of protective ozone over the Arctic this year, scientists say. The ozone layer in the stratosphere, located about 15 to 35 kilometres above the Earth's surface, protects the Earth from the sun's ultraviolet rays and harmful effects such as skin cancer.

While an ozone hole has formed in the stratosphere over the Antarctic each spring since the mid 1980s, a paper published in Nature on Sunday marks the first time scientists have reported a comparable loss over the Arctic. "We've seen something unprecedented," said Kaley Walker, a University of Toronto atmospheric scientists who was part of the international team that conducted the study.

"The amount of depletion and how little ozone there was over certain altitudes is something we haven't seen before." The team concluded that the huge amount of ozone loss was linked to a period of extreme cold in the stratosphere that lasted 30 days longer this year than in any previously studied Arctic winter.


Posted by Amanda Graham – 4 October 2011; 11:53:55 PM – Permalink  

Model provides successful seasonal forecast for the fate of Arctic sea ice

(University of Washington press release, 22 September 2011) -- Relatively accurate predictions for the extent of Arctic sea ice in a given summer can be made by assessing conditions the previous autumn, but forecasting conditions more than five years into the future depend on understanding the impact of climate trends on the ice pack, new research shows. Current conditions form an important starting point that governs how the ice responds to weather in the course of a few years, University of Washington-led research shows. But eventually climate trends overtake that starting point as the primary influence on the overall predictability of sea ice conditions.

"The Arctic is one of the places where conditions are changing the fastest of any climate system in the world," said Edward Blanchard-Wrigglesworth, a UW doctoral student in atmospheric sciences. "Current trends are so strong that it takes five years to establish a new mean." Blanchard-Wrigglesworth is lead author of a paper explaining the research published Wednesday (Sept. 21) in Geophysical Research Letters. Co-authors are Cecilia Bitz, a UW atmospheric sciences professor, and Marika Holland of the National Center for Atmospheric Research in Colorado.

Research from the National Snow and Ice Data Center indicates the low point of this summer's Arctic sea ice cover was 36 percent less than the average minimum from 1979 through 2000, and was just a fraction above the record low in 2007. In the new study, the scientists used the Community Climate System Model version 4, one of only a few models that have successfully simulated the rate of Arctic sea ice decline that has occurred so far. They found that measurements of ice thickness and area in September could provide a good gauge for what the ice expanse would be like at its low ebb the following summer, July through September.

Such predictions are important for shipping – knowing whether the Northeast and Northwest passages might be ice-free in summer, for example – or for natural resource interests such as oil exploration. They also are important for native populations who depend on the sea ice for their livelihoods and to conservationists trying to preserve species such as polar bears.


Posted by Amanda Graham – 27 September 2011; 2:56:54 PM – Permalink  

800,000 years of Greenland's abrupt climate variability

(Cardiff University press release via Physorg.com, 8 September 2011) -- An international team of scientists, led by Dr Stephen Barker of Cardiff University, has produced a prediction of what climate records from Greenland might look like over the last 800,000 years. Drill cores taken from Greenland's vast ice sheets provided the first clue that Earth's climate is capable of very rapid transitions and have led to vigorous scientific investigation into the possible causes of abrupt climate change.

Such evidence comes from the accumulation of layers of ancient snow, which compact to form the ice-sheets we see today. Each layer of ice can reveal past temperatures and even evidence for the timing and magnitude of distant storms or volcanic eruptions. By drilling cores in the ice scientists have reconstructed an incredible record of past climates. Until now such temperature records from Greenland have covered only the last 100,000 years or so. The team's reconstruction is based on the much longer ice core temperature record retrieved from Antarctica and uses a mathematical formulation to extend the Greenland record beyond its current limit.

Dr Barker, Cardiff School of Earth and Ocean Sciences said: "Our approach is based on an earlier suggestion that the record of Antarctic temperature variability could be derived from the Greenland record. "However, we turned this idea on its head to derive a much longer record for Greenland using the available records from Antarctica."

The research published in the journal Science demonstrates that abrupt climate change has been a systemic feature of Earth's climate for hundreds of thousands of years and may play an active role in longer term climate variability through its influence on ice age terminations.


Posted by Amanda Graham – 9 September 2011; 4:51:32 PM – Permalink  

Newly discovered Icelandic current could change climate picture

(National Science Foundation press release, 23 August 2011) -- If you'd like to cool off fast in hot summer weather, take a dip in a newly discovered ocean current called the North Icelandic Jet (NIJ). You'd need to be far, far below the sea's surface near Iceland, however, to reach it. Scientists have confirmed the presence of the NIJ, a deep-ocean circulation system off Iceland. It could significantly influence the ocean's response to climate change.

The NIJ contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), critically important for regulating Earth's climate. As part of the planet's reciprocal relationship between ocean circulation and climate, the AMOC transports warm surface water to high latitudes where the water warms the air, then cools, sinks and returns toward the equator as a deep flow. Crucial to this warm-to-cold oceanographic choreography is the Denmark Strait Overflow Water (DSOW), the largest of the deep, overflow plumes that feed the lower limb of the AMOC and return the dense water south through gaps in the Greenland-Scotland Ridge.

For years it has been thought that the primary source of the Denmark Overflow was a current adjacent to Greenland known as the East Greenland Current. However, this view was recently called into question by two oceanographers from Iceland who discovered a deep current flowing southward along the continental slope of Iceland. They named the current the North Icelandic Jet and hypothesized that it formed a significant part of the overflow water. Now, in a paper published in the August 21st online issue of the journal Nature Geoscience, the team of researchers — including the two Icelanders who discovered the current — has confirmed that the Icelandic Jet is not only a major contributor to the DSOW but "is the primary source of the densest overflow water." "We present the first comprehensive measurements of the NIJ," said Robert Pickart of the Woods Hole Oceanographic Institution in Massachusetts, one of the co-authors of the paper.


Posted by Amanda Graham – 26 August 2011; 2:44:18 PM – Permalink  

With climate changes, polar bear and brown bear lineages intertwine

(Terra Daily, 15 July 2011) -- Polar bears' unique characteristics allow them to survive in one of the most extreme environments on Earth, but that survival is now threatened as rising temperatures and melting ice reshape the Arctic landscape. Now it appears that the stress of climate change, occurring both long ago and today, may be responsible for surprising twists in the bears' history and future as well.

According to DNA evidence reported in the July 7th Current Biology, a Cell Press publication, polar bears and brown bears have mated successfully many times in the last 100,000 years. As a result of some of those pairings, the polar bears of today also have unexpected Irish roots.

"We found that brown bears and polar bears, which are hybridizing today in the wild, have been hybridizing opportunistically throughout the last 100,000 years and probably longer," said Beth Shapiro of The Pennsylvania State University, noting recent sightings of hybrid adults in Canada. "Generally, this seems to happen when climate changes force the bears to move into each others' habitat. When they come into contact, there seems to be little barrier to them mating."

The researchers used patterns in mitochondrial DNA sequence to trace the bears' evolutionary history. Mitochondria are cellular components with their own DNA and are passed on from mother to child. By extracting and sequencing those mitochondrial genomes from fossils collected from all over the world, the researchers were able to observe how the bears' maternal lineages have shifted in space and over time. They then correlated those patterns with changes in the environment and in the bears' habitats.

"This approach provides a means to go back in time and directly measure the movement of species in response to past climate change," said study author Daniel Bradley of Trinity College Dublin. The study shows that the modern polar bears' maternal line (from female ancestor to their descendants of either sex) descends from a recent hybridization with an extinct population of brown bears that lived in the vicinity of modern-day Britain and Ireland, not from bears living off the coast of Alaska as many believed. That hybridization event most likely occurred just prior to or during the last ice age, they report.


Posted by Amanda Graham – 15 July 2011; 12:14:21 PM – Permalink  

More Arctic shipping will up local pollution: Study

(Nunatsiaq News via Montreal Gazette, 12 July 2011) -- With two to four months of ice-free conditions forecast for the Northwest Passage by 2030, scientists are now looking at what more shipping traffic will mean for the circumpolar region. "The melting of Arctic sea-ice will effectively unlock the Arctic Ocean, leaving it increasingly open to human activity — particularly oil and gas extraction and shipping," say scientists at the Oslo, Norway-based Center for International Climate and Environment Research, the Det Norske Veritas foundation and Statistics Norway. As new circumpolar shipping routes open, climate-warming and polluting emissions from shipping will rise in the Arctic in places where these have never been seen before, they say in a new study published in the journal Atmospheric Chemistry and Physics. And these have the potential to increase Arctic warming.

"The potential increase in Arctic activities and emissions will not only have an impact on the global climate, but may also impact on regional temperature trends," they say. Previous research suggests that ship emissions could increase warming in the Arctic — a region that's already experiencing a higher level of warming than others. As the location of oil and gas production moves into remote Arctic places requiring more ship transport, there will be a "rapid growth" in emissions from oil and gas transport by ship. Arctic shipping emissions will increase faster than the global average and are expected to rise by up to 25 per cent by 2050, the scientists say. As well, levels of ground-level ozone are expected to double or triple as Arctic shipping traffic moves away from community re-supply, fishing and tourism. This ozone affects plants' ability to soak up the greenhouse gas carbon dioxide from the atmosphere, accelerating warming.


Posted by Amanda Graham – 13 July 2011; 11:39:34 AM – Permalink  

Humans stressing out skittish caribou

(University of Washington press release via Futurity.org, 27 June 2011) -- The caribou population has been declining in the region for several decades causing speculation that the entire population could be gone in 70 years. Further, in the area of the petroleum-rich Athabasca Oil Sands in the northern part of the Canadian province, some researchers predict they could disappear in as little as 30 years. While the drop in caribou in recent decades is certain, populations have held relatively steady in the last four years, says Samuel Wasser, conservation biologist at the University of Washington. In a new study, published in the journal Frontiers in Ecology and the Environment, Wasser calls for controlling the impact of human activities before resorting to more drastic actions such as removing wolves from the area. ...

Scat samples from caribou, moose, and wolves, well preserved because of sub-freezing temperatures, were collected in the winters of 2006, 2007, and 2009. In 2009, four teams of highly trained scat-detection dogs led to the recovery of 2,000 samples of caribou, moose, and wolf scat in 10 weeks. In examining the samples, researchers determined habitat preferences for each species, their abundance, the type and quality of food consumed, and hormone levels that could indicate whether the animals were under psychological or nutritional stress, or both.

Deer were found to make up 80 percent of wolves’ diet, with caribou and moose each accounting for about 10 percent. Moose favored habitat associated with food and didn’t seem particularly concerned about people. The result was that their scat had low levels of stress hormones and high levels of nutrition hormones. But caribou proved to be much more skittish. They chose open, flat areas where, presumably, they could see and hear predators and escape. That also made it easier for them to see and hear humans on the landscape. Their scat reflected high stress and low nutrition in areas nearer roads when humans were most active. It turned out that wolves mostly favored areas inhabited by their favorite food source, deer, which also is habitat with few caribou.

Removing wolves could actually have unintentional consequences, Wasser says, because with a much-reduced wolf population, the number of deer would probably increase rapidly. The deer could alter the habitat and perhaps reduce the caribou food supply. Deer also carry multiple diseases that could jump to the caribou population. Until there is evidence to the contrary, changing human activity patterns is safer, he says.


Posted by Amanda Graham – 1 July 2011; 1:22:02 AM – Permalink  

Will global climate change enhance boreal forest growth?

(American Journal of Botany press release, 17 May 2011) -- With an increasingly warmer climate, there is a trend for springs to arrive earlier and summers to be hotter. Since spring and summer are the prime growing seasons for plants -- when flowers bloom and trees increase in girth and height -- do these climate changes mean greater seasonal growth for plants? This is a critical question for forest management, especially in the boreal region -- an area particularly sensitive to the effects of climate change.

Dr. Jian-Guo Huang, currently a post-doc at the University of Alberta, and colleagues from the University of Quebec at Montreal were interested in assessing whether a potentially extended growing season affects stem xylem formation and growth in black spruce (Picea mariana) in Western Quebec, Canada. They published their findings in the May issue of the American Journal of Botany. ... By taking microcore samples from black spruce trees at three different latitudes ranging from 47.5o to 50oN in Western Quebec throughout the growing season (May-September) in 2005 and 2006, Huang and colleagues were able to determine when xylem cell production began and ended, as well as the pattern of xylem cell growth. They then compared these data to soil and air temperature and precipitation data gathered from local climate stations. ...

When the authors examined the pattern of xylem cell initiation, they found an interesting correlation with patterns in air temperatures in the two years. Across all three sites, xylem cell production in black spruce trees started earlier in 2006 than in 2005, corresponding with an earlier spring (and warmer May temperatures) in 2006 -- indicating a positive relationship between temperature and onset of xylem production. ... "Our study implies that despite the expected occurrence of earlier phenological development due to early spring climate warming, boreal trees like Picea mariana might not be producing wider rings if cold temperatures occur later in the growing season in June to August," Huang said. "These results may challenge the view that boreal trees could be benefiting from spring warming to enhance growth." Thus, not only is the timing of the onset of spring important, but the amplitude of summer warming temperatures also plays a role in wood production.


Posted by Amanda Graham – 17 May 2011; 2:46:51 PM – Permalink  

Polar 5 has returned from spring measurements in the high Arctic

(Alfred Wegener Institute for Polar and Marine Research press release via redOrbit, 16 May 2011) -- The research aircraft Polar 5 of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association returned to Bremerhaven from a six-week expedition in the high Arctic on May 6. Joint flights with aircraft of the European and American space agencies (ESA and NASA) were a novelty in sea ice research. Simultaneous measurements with a large number of sensors on three planes underneath the CryoSat-2 satellite led to unique data records. Furthermore, the international team composed of 25 scientists and engineers collected data on trace gases, aerosols and meteorological parameters that will be evaluated at the research institutes involved in the coming months.

The route of the Polar 5 of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association took it from Barrow (Alaska) via Inuvik, Resolute Bay, Eureka, Alert (all in northern Canada) and Station Nord (Greenland) all the way to Longyearbyen on Spitsbergen. These sites were the base stations for the measurement flights to the uninhabited Arctic areas. The total flight time, including measurements and travel time, came to 130 hours. Temperatures  below minus 30°C in some cases were a challenge for both team and material.

One of the key aspects of the expedition were large-scale sea ice thickness measurements in the inner Arctic, in which researchers of the Alfred Wegener Institute and the University of Alberta cooperated closely. For this purpose they used a four meter long electromagnetic ice thickness sensor, called EM Bird. The Polar 5 towed the sensor on an 80 meter long rope at a height of 15 meters above the ice surface for the surveys. A preliminary evaluation of the measurement results shows that one-year-old sea ice in the Beaufort Sea (north of Canada/Alaska) is about 20-30 centimeters thinner this year than in the two previous years. In 2009 the ice thickness was 1.7 meters on average, in 2010 1.6 meters and in 2011 around 1.4 meters. “I expect that this thin one-year-old sea ice will not survive the melting period in summer,” Dr. Stefan Hendricks assesses the situation. In several weeks his colleagues from the sea ice group at the Alfred Wegener Institute will present their model calculations for the sea ice minimum in 2011, which will also include the data now collected.


Posted by Amanda Graham – 16 May 2011; 12:03:15 PM – Permalink  

New study warns of Arctic mercury pollution; high levels found in wildlife

(AP via Washington Post, 5 April 2011) -- STOCKHOLM — Global mercury emissions could grow by 25 percent by 2020 if no action is taken to control them, posing a threat to polar bears, whales and seals and the Arctic communities who hunt those animals for food, an authoritative international study says.

The assessment by a scientific body set up by the eight Arctic rim countries also warns that climate change may worsen the problem, by releasing mercury stored for thousands of years in permafrost or promoting chemical processes that transform the substance into a more toxic form.

“It is of particular concern that mercury levels are continuing to rise in some Arctic species in large areas of the Arctic,” despite emissions reductions in nearby regions like Europe, North America and Russia, the Arctic Monitoring and Assessment Program, or AMAP, said.


Posted by Amanda Graham – 5 May 2011; 11:52:08 AM – Permalink  

Valdez marine life slow to recover after 1964 quake [mp3]

(Dan Bross/KUAC – Fairbanks via APRN, 26 April 2011) -- University of Alaska Fairbanks research shows tiny marine life in Port Valdez was slow to recover following the 1964 earthquake. UAF scientists tracked invertebrates in deep water and intertidal zones of Port Valdez following the 9.2 magnitude quake.  Their findings were recently published in the Journal: Marine Environmental Research.  Assistant Research professor Arny Blanchard, says it took decades for some species to recover after the quake moved massive amounts of sediment over the deep sea floor.

Blanchard says a study led by UAF’s Dr. Howard Feder that looked at the tsunami scoured near shore environment of Port Valdez, also showed drawn out recovery for some species, like mussels. Blanchard says the research may transfer to other more recently earthquake impacted areas like Japan and Indonesia.

Blanchard says the shape of the glacial formed fjord at Port Valdez restricts water exchange between surface and deeper environments, a challenge to rebuilding marine life after a catastrophic event like an earthquake and tsunami.


Posted by Amanda Graham – 29 April 2011; 2:24:34 PM – Permalink  ann-20110426-04.mp3

Changes in Arctic Ocean may affect Europe’s climate

(Fort Frances Times, 12 April 2011) -- New research suggests changes in the Arctic Ocean could affect the climate of coastal Europe. “Large regional changes could be in store if the ocean circulation changes,” said Laura de Stern of the Royal Netherlands Institute for Sea Research. De Stern is the lead author of a major international study on the northern seas released last week. One of the report’s findings is that the Arctic Ocean holds a vast pool of relatively fresh water. Much of it comes from rivers such as Canada’s Mackenzie and Russia’s Lena. That pool—now larger than 7,500 cubic km—is contained in the Canada Basin off the coast of the Northwest Territories and Yukon by a pattern of wind circulation called the Beaufort Gyre. But the gyre changes in strength. When it weakens, the fresher water it has kept concentrated in the Arctic is released to filter into the North Atlantic.

“This is a natural phenomenon,” said contributor Mike Steele of the University of Washington. “[The gyre] tends to collect it in some years, and in other years the gyre will shrink and then it’ll sort of release the fresh water,” he explained. Recent data suggests climate change may be increasing the amount of fresh water pouring into the Arctic Ocean. A study by Germany’s Alfred Wegener Institute released in March found the upper layers of the northern ocean already may be 20 percent less salty than they were in the 1990s. The data points to increasingly larger and fresher releases of water from the Arctic Ocean into the North Atlantic. “These Arctic outflow surges can significantly change the densities of marine surface waters in the extreme North Atlantic,” said de Stern.


Posted by Amanda Graham – 27 April 2011; 3:08:08 PM – Permalink  

Melting ice on Arctic islands a major player in sea level rise

(PhysOrg, 20 April 2011) -- Melting glaciers and ice caps on Canadian Arctic islands play a much greater role in sea level rise than scientists previously thought, according to a new study led by a University of Michigan researcher.

The 550,000-square-mile Canadian Arctic Archipelago contains some 30,000 islands. Between 2004 and 2009, the region lost the equivalent of three-quarters of the water in Lake Erie, the study found. Warmer-than-usual temperatures in those years caused a rapid increase in the melting of glacier ice and snow, said Alex Gardner, a research fellow in the Department of Atmospheric, Oceanic and Space Sciences who led the project. The study is published online in Nature on April 20.

"This is a region that we previously didn't think was contributing much to sea level rise," Gardner said. "Now we realize that outside of Antarctica and Greenland, it was the largest contributor for the years 2007 through 2009. This area is highly sensitive and if temperatures continue to increase, we will see much more melting."


Posted by Amanda Graham – 27 April 2011; 2:43:04 PM – Permalink  

A good time to be a wolverine

(Sveriges Radio, 10 April 2011) -- The number of wolverines in Sweden has doubled in the last ten years and the small predators are spreading outside their former habitats in the far north-west. The small brown creatures can grow up to 20kg and are sometimes taken for a small bear. They are a protected species in Sweden, where there are thought to be about 600-600 wolverines. Reindeer herders often see wolverines as a possible threat, but researchers say that wolverines mostly live off carcasses left behind by larger predators.

Jens Persson is the head researcher in the wolverine project at Sweden's University of Agriculture. He says to Swedish Radio News that the success of other predators like wolves, who kill elk, could be the reason why wolverines are getting better fed and reproducing more. Jens Persson says that the combined wolverine population of Sweden and Norway must be over 1,000, and that there is no foreseeable threat against this nordic beast today.


Posted by Amanda Graham – 11 April 2011; 4:19:32 PM – Permalink  

Common nanoparticles found to be highly toxic to Arctic ecosystem

(Queen's University press release, 6 April 2011) -- Queen's researchers have discovered that nanoparticles, which are now present in everything from socks to salad dressing and suntan lotion, may have irreparably damaging effects on soil systems and the environment. "Millions of tonnes of nanoparticles are now manufactured every year, including silver nanoparticles which are popular as antibacterial agents," says Virginia Walker, a professor in the Department of Biology. "We started to wonder what the impact of all these nanoparticles might be on the environment, particularly on soil."

The team acquired a sample of soil from the Arctic as part of their involvement in the International Polar Year initiative. The soil was sourced from a remote Arctic site as they felt that this soil stood the greatest chance of being uncontaminated by any nanoparticles.

"We hadn't thought we would see much of an impact, but instead our results indicate that silver nanoparticles can be classified as highly toxic to microbial communities. This is particularly concerning when you consider the vulnerability of the arctic ecosystem." ... The researchers first examined the indigenous microbe communities living in the uncontaminated soil samples before adding three different kinds of nanoparticles, including silver. The soil samples were then left for six months to see how the addition of the nanoparticles affected the microbe communities. What the researchers found was both remarkable and concerning. ...

These pioneering findings by Queen's researchers Niraj Kumar and Virginia Walker and Dowling College's Vishal Shah have been published today in the Journal of Hazardous Materials, the highest ranking journal in Civil Engineering.


Posted by Amanda Graham – 6 April 2011; 3:19:08 PM – Permalink  

Effects of sea-ice loss on biodiversity

(Arctic Council, 5 April 2011) -- Thirty scientists, managers and community experts met in Vancouver, Canada, to develop a technical report on what effects sea-ice reduction has on biodiversity in the Arctic. The Arctic Council Working Group on Conservation of Arctic Flora and Fauna (CAFF), organized and managed the workshop.

The workshop, which took place 22-23 March 2011, considered the following urgent issues: 

  • An overview of sea ice ecosystems and the role of ice in regions where sea ice is integral
  • The potential for wildlife and communities to adapt to a changing sea ice scenario
  • Impacts of reduced sea ice on genetic diversity of species
  • New species likely to establish as a result of reduction in sea ice
  • Positive and negative effects of changes to species composition on other wildlife and people
  • Priority actions that could be taken in support of sea ice-associated biodiversity
  • Information gaps that require targeted research

Building on the workshop's results, the project will develop a technical report on the current status and trends of sea ice-associated biodiversity, including direct effects on marine species and indirect effects on terrestrial species. The report will be finalized during a second workshop to be held in Russia in autumn 2011.  Here, the accompanying conservation, scientific and policy recommendations will also be developed.


Posted by Amanda Graham – 6 April 2011; 2:54:48 PM – Permalink  

Arctic food chain faces disruption: scientists

(Nunatsiaq News, 3 March 2011) -- Warming temperatures and melting ice in the Arctic may be causing a progressively earlier bloom of tiny ocean plants in the spring, and this shift could hold consequences for the entire Arctic food chain, say scientists at Scripps Institution of Oceanography in California. The scientists found “significant trends” towards earlier blooms of these plants, called phytoplankton, in about 11 per cent of the area of the Arctic Ocean closest to the North Pole. During the one- to two-week period in the spring, these blooms stimulate production of zooplankton, microscopic marine animals, which become a food source for fish and whales.

 “The spring bloom provides a major source of food for zooplankton, fish and bottom-dwelling animals,” said oceanographer Mati Kahru, in a March 2 news release from the Scripps Institution. “The advancement of the bloom time may have consequences for the Arctic ecosystem.” Scientists plotted the yearly spring bloom of these tiny plants at the base of the ocean food chain-in the Arctic Ocean, notes the news release. And they found the timing of these blooms has occurred earlier each year for more than 10 years.

By analyzing satellite data, they determined that the spring bloom has come up to 50 days earlier in some areas over that period. The earlier Arctic blooms occurred in areas where there’s been less ice cover. These openings have created gaps that make early blooms possible, say the researchers, who published their findings in this month’s edition of the journal Global Change Biology.


Posted by Amanda Graham – 3 March 2011; 10:29:32 PM – Permalink  

Shrinking tundra, advancing forests: how the Arctic will look by century's end

(University of Nebraska-Lincoln press release via EurekAlert, 3 March 2011) -- Imagine the vast, empty tundra in Alaska and Canada giving way to trees, shrubs and plants typical of more southerly climates. Imagine similar changes in large parts of Eastern Europe, northern Asia and Scandinavia, as needle-leaf and broadleaf forests push northward into areas once unable to support them. Imagine part of Greenland's ice cover, once thought permanent, receding and leaving new tundra in its wake. Those changes are part of a reorganization of Arctic climates anticipated to occur by the end of the 21st century, as projected by a team of University of Nebraska-Lincoln and South Korean climatologists.

In an article to be published in a forthcoming issue of the scientific journal Climate Dynamics, the research team analyzed 16 global climate models from 1950 to 2099 and combined it with more than 100 years of observational data to evaluate what climate change might mean to the Arctic's sensitive ecosystems by the dawn of the 22nd century. The study is one of the first to apply a specific climate classification system to a comprehensive examination of climate changes throughout the Arctic by using both observations and a collection of projected future climate changes, said Song Feng, research assistant professor in UNL's School of Natural Resources and the study's lead author.

Based on the climate projections, the new study shows that the areas of the Arctic now dominated by polar and sub-polar climate types will decline and will be replaced by more temperate climates – changes that could affect a quarter to nearly half of the Arctic, depending on future greenhouse gas emission scenarios, by the year 2099. Changes to Arctic vegetation will naturally follow shifts in the region's climates: Tundra coverage would shrink by 33 to 44 percent by the end of the century, while temperate climate types that support coniferous forests and needle-leaf trees would push northward into the breach, the study shows.

"The expansion of forest may amplify global warming, because the newly forested areas can reduce the surface reflectivity, thereby further warming the Arctic," Feng said. "The shrinkage of tundra and expansion of forest may also impact the habitat for wildlife and local residents."


Posted by Amanda Graham – 3 March 2011; 10:15:04 PM – Permalink  

Beaufort Sea fish survey released to help understand impacts from industry, climate change

(The Arctic Sounder, 21 February 2011) -- The Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) today announced the release of a comprehensive baseline study of fish populations in the western Beaufort Sea, the agency said in a written statement. The results of the study will provide future researchers and decision makers with an important baseline – a way to help measure changes over time caused by factors such as industry activity and climate change.

"Our comprehensive offshore energy strategy calls for increased environmental studies off the coast of Alaska," said BOEMRE Director Michael R. Bromwich. "The results of this study will contribute greatly to our knowledge of the fish populations in the Beaufort Sea. When combined with the other scientific work we are conducting in the region, this study will enable us to make better decisions regarding responsible offshore energy development in Alaska."

The new study, Beaufort Sea Marine Fish Monitoring 2008: Pilot Survey and Test of Hypotheses (BOEMRE OCS Report 2010-048), was conducted in an area located over the western Beaufort Sea. Researchers measured depth, water temperature, and salinity across the area and collected samples of the various fish and invertebrate populations in that area. The survey was carried out through an interagency agreement with National Oceanic and Atmospheric Administration (NOAA) and is the first such survey in what is anticipated to be a series of interagency studies to better understand the diversity and distribution of fish populations in the Beaufort Sea. In the summer of 2011, the survey will be replicated in the central Beaufort Sea through an agreement with the University of Alaska Fairbanks' School of Fisheries and Ocean Sciences.

The study is available online at: http://www.alaska.boemre.gov/reports/2010rpts/2010_048.pdf


Posted by Amanda Graham – 25 February 2011; 11:38:22 AM – Permalink  

New study illustrates shifting biomes in Alaska

(Woods Hole  press release via RedOrbit, 21 February 2011) -- A new study released today in the EarlyView of Ecology Letters addresses forest productivity trends in Alaska, highlighting a shift in biomes caused by a warming climate. The findings, conducted by scientists at the Woods Hole Research Center and three other institutions based in Alaska and France, linked satellite observations with an extensive and unique tree-ring data set. Patterns observed support current hypotheses regarding increased growth of evergreen forest at the margins of present tundra and declining productivity at the margins of temperate forest to the south.

This study provides a regional picture of forest productivity which did not previously exist. According to lead author Pieter Beck, a post-doctoral fellow at WHRC, "The results provide evidence for the initiation of a biome shift in response to climate change, and indicate that some ecosystem models may be missing fundamental changes taking place in the circumpolar region." He adds that "while the findings contrast with some recent model predictions of increased high latitude vegetation productivity, they are consistent with longer-term projections of global vegetation models."


Posted by Amanda Graham – 23 February 2011; 11:56:31 AM – Permalink  

New 2D Web Mapping Available: Arctic Research Mapping Application (ARMAP)

(ARMAP news release via ArcticInfo, 18 February 2011) -- The Arctic Research Mapping Application (ARMAP) includes a new ARMAP 2D. This interactive mapping solution joins a suite of online maps and services that support arctic science. It is fast, intuitive, and optimized for high latitudes. With the new ARMAP 2D, you can earn more about research projects in your region of interest or scientific discipline; explore available data or possible collaborations; and use the online mapping tools to meet your own project's specific goals.

The new ARMAP 2D is available as a beta release online, at http://armap.org

The previous version of ARMAP 2D, which is based on outdated IMS technology, is still available. Other resources on the website include ARMAP in Google Earth, ARMAP 3D, a variety of web services, and spatial datasets customized for arctic research. ARMAP is funded by the National Science Foundation's Office of Polar Programs, and is a collaborative effort among the Systems Ecology Laboratory at the University of Texas at El Paso, Nuna Technologies, the INSTAAR QGIS Laboratory, and CH2M HILL Polar Services. For further information or to play with the application, please go to http://armap.org


Posted by Amanda Graham – 20 February 2011; 4:20:31 PM – Permalink  

Hibernating bears yield surprises

(Washington Post, 18 February 2011) -- In the woods of Alaska, five black bears snoozed all winter while researchers recorded every detail of their slow-motion daily drama for the first time ever. It turns out that unlike dozens of other hibernating mammals, the bears maintained a high body temperature throughout five months of inactivity. And when the bears emerged in mid-April, they stayed groggy, with their metabolic rate remaining at about half that of summer levels for two to three weeks.

Brian Barnes, director of the Institute of Arctic Biology at the University of Alaska at Fairbanks, said the research, unveiled Thursday at the annual meeting of the American Association for the Advancement of Science in Washington, could one day aid patients with strokes and serious injuries.

"If we can uncover the way hibernators turn down their demand for oxygen, you can imagine developing a therapy . . . to put someone in stasis, a protected state," Barnes said. "That would give you more time. It would expand the 'golden hour' where it's critical to reach medical care to a golden day or a golden week." An infrared camera captures an Alaskan black bear in deep hibernation. That and a graphic explaining the bears' hibernation can be seen at wapo.st/bearstudy


Posted by Amanda Graham – 18 February 2011; 3:03:35 PM – Permalink  

Researchers warn Arctic fishing under-reported

(Allan Dowd/Reuters, 4 Febraury 2011) -- The amount of fish caught in the Arctic has been dramatically under-reported for decades, making the northern ocean environment appear far more pristine than it really is, according to a new study. An estimated 950,000 tonnes of fish were caught in Russian, Canadian and U.S. Arctic waters between 1950 and 2006, which is 75 times higher than reported by the United Nation's agency that records catch levels, according to Canadian researchers.

Ineffective reporting "has given us a false sense of comfort that the Arctic is still a pristine frontier when it comes to fisheries," lead researcher Dirk Zeller of the University of British Columbia said in a written statement. The results of the study were published this week in the journal Polar Biology. The researchers said they collected data on fish catches from a variety of sources in the region, including those kept by indigenous people, and compared it to what was reported to the U.N.'s Food and Agriculture Organization. The researchers estimate that, between 1950 and 2006, 89,000 tonnes of fish were caught in Alaskan coastal waters in the Arctic and 94,000 tonnes in Canadian waters, but neither Canada nor the United States supplied that data to the U.N.

An estimated 770,000 tonnes of fish were caught in Russian waters off Siberia, far above the 12,700 tonnes reported by the United Nations, according to the study. The researchers said that most Arctic conservation efforts concentrate on protecting animal such as seals and polar bears, and they warned that the marine mammals will not survive if the rest of the region's ecosystem is neglected. The researchers said the problems could become worse if climate change pushes more fish into polar waters and melting sea ice allows greater access by the world's fishing fleets. Researchers at the university issued a study in December warning that global fleets were running out of fishing grounds, and the waters of the Arctic and Antarctic were among the few areas remaining for exploitation.


Posted by Amanda Graham – 5 February 2011; 11:05:21 PM – Permalink  

Arctic sea ice controls the release of mercury

(CNRS press release, 17 January 2011) -- A French-American team, including researchers from CNRS, IRD, the Université Paul Sabatier and the Université de Pau, has recently highlighted a new role that sea ice plays in the mercury cycle in the Arctic. By blocking sunlight, sea-ice could influence the breakdown and transfer into the atmosphere of toxic forms of mercury present in the surface waters of the Arctic Ocean. These results, which suggest that climate plays a key role in the mercury cycle and that the release of mercury into the atmosphere could be accentuated by the melting of Arctic sea ice, are published in the journal Nature Geoscience (February issue).

Mercury (Hg) is the only heavy metal that is essentially found in gaseous form in the atmosphere. Since the industrial revolution, emissions of anthropogenic Hg resulting from the combustion of fossil fuels have exceeded natural emissions. Both anthropogenic emissions and natural emissions (which mainly stem from the oceans and gases released by volcanoes) reach the Polar Regions under the action of atmospheric currents. In this way, fallout from global atmospheric pollution contributes to depositing mercury in Arctic ecosystems, even though these are far away from major anthropogenic emission sources. In the Arctic atmosphere, elementary mercury is oxidized into a form that deposits easily in the cryosphere (snow, ice). Then, when the ice melts, this oxidized form can in turn be re-mobilized and transformed, via physicochemical and biological processes, into a toxin: methylmercury (CH3Hg). It is this toxic form that is ingested by living organisms. It accumulates throughout the food chain and can reach concentrations one million times higher than those measured in surface waters at the very top of the chain.


Posted by Amanda Graham – 19 January 2011; 11:52:36 AM – Permalink  

Being good moms couldn’t save the woolly mammoth

(Western News, 20 December 2010) -- New research from The University of Western Ontario leads investigators to believe that woolly mammoths living north of the Arctic Circle during the Pleistocene Epoch (approx. 150,000 to 40,000 years ago) began weaning infants up to three years later than modern day African elephants due to prolonged hours of darkness.  This adapted nursing pattern could have contributed to the prehistoric elephant’s eventual extinction. The findings were published recently in the journal, Palaeogeography, Palaeoclimatology, Palaeoecology.

By studying the chemical composition of adult and infant mammoth teeth, Jessica Metcalfe, an Earth Sciences PhD student working with professor Fred Longstaffe, was able to determine woolly mammoths that once inhabited Old Crow, Yukon, didn’t begin eating plants and other solid foods before the age of two (and perhaps as late as three) and considers predatory mammals like saber-toothed cats and a lack of sufficient vegetation to be the secondary reasons for delayed weaning.


Posted by Amanda Graham – 23 December 2010; 12:03:27 AM – Permalink  

As glaciers melt, scientists seek new data on rising seas

(Justin Gillis/New York Times, 13 November 2010) -- TASIILAQ, Greenland - With a tense pilot gripping the stick, the helicopter hovered above the water, a red speck of machinery lost in a wilderness of rock and ice. To the right, a great fjord stretched toward the sea, choked with icebergs. To the left loomed one of the immense glaciers that bring ice from the top of the Greenland ice sheet and dump it into the ocean. Hanging out the sides of the craft, two scientists sent a measuring device plunging into the water, between ice floes. Near the bottom, it reported a temperature of 40 degrees. It was the latest in a string of troubling measurements showing that the water was warm enough to melt glaciers rapidly from below.

“That’s the highest we’ve seen this far up the fjord,” said one of the scientists, Fiammetta Straneo.

The temperature reading was a new scrap of information in the effort to answer one of the most urgent — and most widely debated — questions facing humanity: How fast is the world’s ice going to melt? Scientists long believed that the collapse of the gigantic ice sheets in Greenland and Antarctica would take thousands of years, with sea level possibly rising as little as seven inches in this century, about the same amount as in the 20th century. But researchers have recently been startled to see big changes unfold in both Greenland and Antarctica.

As a result of recent calculations that take the changes into account, many scientists now say that sea level is likely to rise perhaps three feet by 2100 — an increase that, should it come to pass, would pose a threat to coastal regions the world over. And the calculations suggest that the rise could conceivably exceed six feet, which would put thousands of square miles of the American coastline under water and would probably displace tens of millions of people in Asia.


Posted by Amanda Graham – 14 November 2010; 12:58:33 AM – Permalink  

Brown bears better adapted to warming Arctic, scientists say

(Jane George/Nunatsiaq News, 8 November 2010) -- The polar bear is the only living bear that eats only a diet of meat, having evolved to Arctic conditions less than a million years ago from the I’ll-eat-anything brown bear. So, now there’s increasing attention from researchers on what polar bears will eat when their supply of seal pups decreases along with the sea ice. If Arctic warming continues, one recent study predicts polar bears may turn to snow goose eggs to fill their bellies.

Another study, published Nov. 5 on an on-line research journal called PLOS One, says polar bears may be at a disadvantage precisely because they adapted to this diet of seals. The polar bear evolved smaller molars and a low, slender skull which allow it to “efficiently process” seal flesh and blubber. But if polar bears can’t find enough of their favorite foods, they may suffer from competition with northward moving brown bear populations for resources that they are “ill-equipped” to use, say the authors of a paper that looks at the consequences of rapid evolution in polar bears. Their research shows an “extremely rapid evolution” of brown bears into polar bears which produced a skull which is less suited to processing tough, hard-to chew diets with lots of vegetation.

Although the heads and muscle-power of two species are similar, tests reveal the polar bear’s skull is a “weaker, less work-efficient structure,” and does not appear well suited to large amounts of chewing, the study’s authors say. Compared with other bears, polar bears have low flat skulls with high-sitting eyes, which likely developed as an advantage so they could thrust their heads into breathing holes or pupping dens. Because polar bears feed almost exclusively on young ringed and bearded seals, they don’t need as large skulls as in as lions or wolves that regularly eat prey larger than themselves, the study says. And they also lack the well-developed “blade-like” teeth because polar bears feed almost exclusively on blubber and flesh. These, unlike bone, require little or no chewing or tearing prior to swallowing, the study notes.

Brown bears eat animals when available, but they also eat large amounts of plants in the summer, including grasses which require a lot of work before they can be swallowed. So, increased competition from brown bears expanding their range northward is likely to present “a significant challenge” to polar bears, the study concludes, pointing to areas where Arctic foxes overlap with red foxes, which end up controlling prime feeding and denning areas. Brown bears may have the upper hand as the Arctic warms, and the polar bear, which the study calls one of the most striking examples of rapid evolution, “may be lost as quickly as it appeared.”


Posted by Amanda Graham – 8 November 2010; 8:20:29 PM – Permalink  

Killer whales endanger otters in Southwest Alaska, report says

(Mary Pemberton/Anchorage Daily News, 16 October 2010) -- A report by government scientists identifies killer whales as the No. 1 reason there are so few sea otters in southwest Alaska. The U.S. Fish and Wildlife Service's proposed five-year, $15 million recovery plan for sea otters in the Aleutian Islands considered a slew of possible reasons for the perilously low numbers found in some areas. The draft recovery plan released this week said there is only one threat considered to have high importance: predation by killer whales, with sharks perhaps being a factor. Nearly all other factors, including climate change and impacts from humans, were considered to have low importance.

The report said there may be "few actions that can be taken" to mitigate predation by killer whales. "But the sea otter recovery program should search for solutions and be open to novel ideas," the report said. The southwest Alaska sea otter population, which has declined by more than 90 percent in some areas, has been listed as threatened since 2005. In 1976, there were an estimated 94,050 to 128,650 sea otters. Now, there are an estimated 53,674 animals, and perhaps fewer. The recovery plan does identify some other potential threats to sea otters, most importantly the role of disease and whether there is adequate oil-spill response in southwest Alaska. While the report clearly points to killer whales, it also highlights other big concerns, said Brendan Cummings, senior counsel with the Center for Biological Diversity.

"If you had a tanker break up in the Aleutian chain, it could be absolutely catastrophic for sea otters," he said.


Posted by Amanda Graham – 17 October 2010; 1:26:30 AM – Permalink  

Hippo-like mammals once basked in toasty Arctic

(Charles Q. Choi/MSNBC Science, 10 September 2010) --  How did cold-blooded alligators and giant tortoises once thrive well above the Arctic Circle? It turns out the climate in some Arctic locales sometimes never dipped below freezing some 50 million years ago, scientists now reveal. These new findings could foreshadow the impacts of continuing global warming on arctic plants and animals, researchers added. Scientists investigated Ellesmere Island in the High Arctic, which nowadays is one of the coldest, driest environments on Earth, where sparse vegetation and a few mammals eke out life amid tundra, permafrost and ice sheets. Temperatures on the island, which is adjacent to Greenland, range from roughly minus 37 degrees F in winter (minus 38 Celsius) to 48 degrees F (nearly 9 degrees C) in summer. ... However, during the early Eocene period about 50 million years ago, Ellesmere Island was probably similar to swampy cypress forests in the southeastern United States today. Fossils collected there in recent decades by various teams revealed a lush landscape, which hosted giant tortoises, aquatic turtles, alligators, large snakes, flying lemurs, tapirs and hippo-like and rhino-like mammals.

To see what temperatures might have been like back then, Eberle and her colleagues analyzed oxygen isotopes in fossil bones and teeth of mammals, fish and turtles from the island. (Isotopes are atoms of the same element with different numbers of neutrons.) ... The concentrations of lighter and heavier oxygen isotopes found in these fossils match those found in the water the animals drank. This water came down as rain and snow in air masses that developed in the tropics. If the voyage to the poles was cold for the air masses, they likely shed the heavier oxygen isotopes over time, but if the climate was warmer, they probably kept more of their heavier isotopes. In other words, the warmer the area was, the more heavy oxygen isotopes one could find in fossils.

"By looking at a host of animals with different physiologies, we were better able to pin down warm- and cold-month temperatures," Eberle added. The team concluded the average temperatures of the warmest month on Ellesmere Island during the early Eocene were from 66 to 68 degrees F (19 to 20 degrees C), while the coldest-month temperature was about 32 to 38 degrees F (0 to 3.5 degrees C). "Our data gathered from multiple organisms indicate it probably did not get below freezing on Ellesmere Island during the early Eocene, which has some interesting implications," Eberle said.

These new findings could serve as omens of the impact of continuing global warming on arctic plants and animals, Eberle said. Temperatures in the Arctic are rising twice as fast as those at mid-latitudes as greenhouse gases build up in Earth's atmosphere, due primarily to human activities like fossil fuel burning and deforestation, according to climate scientists. "These fossils are really important to our understanding of the Arctic during the height of past global warming and could be the key to a lot of questions we have about current global warming," Eberle said. ...

When it comes to analyzing fossils from the island to learn more about the past and potentially the future, scientists are concerned over a proposal to mine coal at the ancient fossil site. "Sites like this are unique and extremely valuable resources that are of international importance, and shouldn't be allowed to disappear," Eberle said. "Our concern is that coal-mining activities could damage such sites, and they will be lost forever."

The scientists detailed their findings in the August issue of the journal Earth and Planetary Science Letters.



Posted by Amanda Graham – 12 September 2010; 10:15:33 PM – Permalink  

Ice-trapped pollutants poison polar bears' diets

(Deutsche Welle, 20 August 2010) -- The iconic symbol of the Arctic — the polar bear — is under threat from the twin challenges of climate change and lingering chemical pollutants, such as PCBs (polychlorinated biphenyls), which are not breaking down in the region's cold waters. A comprehensive review of research on polar wildlife published recently in the journal Science of The Total Environment has concluded that the retreat of sea ice cover in the Arctic as a result of climate change could increase the exposure of species such as polar bears to a range of man-made chemical compounds, including flame retardants and substances used to harden plastics.

Scientists believe that lingering pollutants, locked up in the polar ice for decades, could be released into the ocean as the ice cover retreats. According to estimates, annual sea-ice cover in the Arctic in the northern summer is now between a quarter and a third less than it was 30 years ago. The world's polar bear population is currently estimated to total between 20,000 and 25,000 specimens, despite the Arctic region's vast size. Polar bears are particularly at risk, according to Bjorn Munro Jenssen, a Norwegian eco-toxicologist and polar bear expert who contributed to the review, because they are at the very top of the Arctic food chain.

"These contaminants are bio-accumulated and bio-magnified up the food chain," said Jenssen. "So the higher you are in the food chain, the higher are the contaminants."The fact that a polar bear's favorite meal is seal does not help matters in any way.

"These contaminants accumulate in fat, and the polar bear only eats the fat of the seals," explained Jenssen. "So they are exposed to huge amounts of fat when they eat one seal — and they eat maybe a few hundred or a thousand seals per year — and then it accumulates." Jenssen emphasizes that the contaminants involved are toxic, even in low concentrations. They can affect a polar bear's hormone system and immune system, which is likely to have an influence on the animals' overall reproduction and survival rates.


Posted by Amanda Graham – 22 August 2010; 12:56:17 PM – Permalink  

Borehole network confirms, permafrost is thawing worldwide

(Victoria Barber/Arctic Sounder, 13 August 2010) -- An expanded network of boreholes across the northern hemisphere has confirmed that permafrost throughout polar and sub-polar regions is thawing, say scientists who studied the topic during International Polar Year. "You look at a whole hemisphere and see the patterns everywhere," said Vladimir Romanovsky, a professor with the snow, ice and permafrost group at the University of Alaska Fairbanks Geophysical Institute, and lead author of a paper documenting the research.

Romanovsky and his colleagues launched a campaign to improve the global network of boreholes for International Polar Year, a science program focused on the Arctic and Antarctic that ran from 2007 to 2009. Boreholes are holes drilled anywhere from 6 feet to over 200 feet into the ground and equipped with sensors to allow scientists to measure soil conditions. The researchers established nearly 300 boreholes, nearly doubling the existing network. "The heart of monitoring is the measuring of the temperatures in boreholes," Romanovsky said.

Using information collected from 575 boreholes located throughout North America, Russia and the Nordic region, researchers found that permafrost temperatures during the International Polar Year were as much as 2 degrees Celsius (35.6 degrees Fahrenheit) warmer than they were 20 or 30 years ago. Also, they found that the rate permafrost changes decreases the closer it gets to 0 degrees Celsius - basically, cold permafrost thaws more quickly than warmer permafrost. Romanovsky, Sharon L. Smith and Hanne H. Christianson published their findings in the April/June 2010 edition of the science publication Permafrost and Periglacial Processes.


Posted by Amanda Graham – 21 August 2010; 8:20:19 PM – Permalink  

Exclusive: Historic Northwest Passage wreckage discovered beneath Beaufort Sea

(Don Martin/Calgary Herald, 28 July 2010) -- MERCY BAY, N.W.T. - The historic ship whose crew discovered Canada’s Northwest Passage has been found 155 years after it was abandoned and sank in this oft-frozen Arctic bay atop isolated Banks Island. The wreck of HMS Investigator was detected in shallow water within days of Parks Canada archeologists launching their ambitious search for the 422-tonne ship from this chilly tent encampment on the Beaufort Sea shoreline.

“It’s sitting upright in silt; the three masts have been removed, probably by ice,” said Ifan Thomas, Parks Canada’s superintendent of the western Arctic Field Unit. “It’s a largely intact ship in very cold water, so deterioration didn’t happen very quickly.” The clear Arctic water makes it possible to glimpse the outline of the ship’s outer deck, which is only eight metres below the surface. Three graves were also found Tuesday. They are undoubtedly the remains of British sailors who succumbed to disease in the final months of the ship’s three-year Arctic ordeal.

 “In anthropological terms, this is the most important shipwreck in history,” said senior marine archeologist Ryan Harris. “It’s a bit like finding a Columbus ship in the Arctic.”


Posted by Amanda Graham – 28 July 2010; 6:11:18 PM – Permalink  

Mitochondrial genome analysis revises view of the initial peopling of North America

(Cold Spring Harbor Laboratory press release, 28 June 2010) -- 29 June 2010 - The initial peopling of North America from Asia occurred approximately 15,000-18,000 years ago, however estimations of the genetic diversity of the first settlers have remained inaccurate. In a report published online today in Genome Research (www.genome.org), researchers have found that the diversity of the first Americans has been significantly underestimated, underscoring the importance of comprehensive sampling for accurate analysis of human migrations. Substantial evidence suggests that humans first crossed into North America from Asia over a land bridge called Beringia, connecting eastern Siberia and Alaska. Genetic studies have shed light on the initial lineages that entered North America, distinguishing the earliest Native American groups from those that arrived later. However, a clear picture of the number of initial migratory events and routes has been elusive due to incomplete analysis.

In this work, an international group of researchers coordinated by Antonio Torroni of the University of Pavia in Italy performed a detailed mitochondrial genome analysis of a poorly characterized lineage known as C1d. Mitochondrial DNA (mtDNA) is passed down through the maternal lineage, and mtDNA sequence markers are extremely useful tools for mapping ancestry. Similar to other haplogroups that were among the first to arrive in North America, C1d is distributed throughout the continent, suggesting that it may have been also present in the initial founding populations. However, C1d has not been well represented in previous genetic analyses, and the estimated age of approximately 7,000 years, much younger than the other founding haplogroups, was likely inaccurate.

To resolve these inconsistent lines of evidence, the group sequenced and analyzed 63 C1d mtDNA genomes from throughout the Americas. This high-resolution study not only confirmed that C1d was one of the founding lineages in North America 15,000 to 18,000 years ago, but revealed another critical insight. "These first female American founders carried not one but two different C1d genomes," said Ugo Perego of the Sorenson Molecular Genealogy Foundation and primary author of the study, "thus further increasing the number of recognized maternal lineages from Beringia."

These findings raise the number of founding maternal lineages in North America to fifteen. Furthermore, this work emphasizes the critical need for comprehensive analysis of relevant populations to gather a complete picture of migratory events. Alessandro Achilli of the University of Perugia, a coauthor of the report, suggests that the number of distinct mitochondrial genomes that passed from Asian into North America is probably much higher. "These yet undiscovered maternal lineages will be identified within the next three to four years," Achilli noted, "when the methodological approach that we used in our study will be systematically applied."

[Note: The article is open source and may be found here.]


Posted by Amanda Graham – 10 July 2010; 10:39:48 PM – Permalink  

New language research supports land bridge evidence

(Mary Beth Smetzer/Fairbanks Daily News-Miner via The Associated Press and via Anchorage Daily News, 6 July 2010) -- FAIRBANKS -- Research on a language connection between Asia and North America supports archaeological and genetic evidence for a Bering Strait land bridge, and the discovery is being endorsed by a growing list of scholars in linguistics and other sciences.  Western Washington University linguistics professor Edward Vajda has been studying the isolated Ket people of Central Siberia. His work is revealing more and more examples of an ancient language connection with the language family of Na-Dene, which includes Tlingit, Gwich'in, Dena'ina, Koyukon, Navajo, Carrier, Hupa, Apache and about 45 other languages.

In 2008, Vajda aired his hypothesis at a symposium in Alaska organized by James Kari of the University of Alaska Native Language Center. Vajda was trained in Slavic languages but became interested in Ket in the late 1980s, when he came across a book in Russian about the near extinct language in Siberia. His interest grew, and over the years he has engaged in extensive research, meeting Ket speakers twice in Germany, in southern Siberia and in Ket villages along the Yenisei River in central Siberia. To reach the remote Ket area, Vajda traveled via six airplanes, three trains and a 4 1/2-hour helicopter ride that sometimes barely cleared the tops of the Siberian spruce forests. Of the 1,200 Ket people, only about 100, all older than 55, still speak the language. ...  

The importance of studying a disappearing language goes far beyond a personal linguistic interest, Vajda explained. "It's a new way to understand human prehistory before there were historians to write it down. Isolated languages like Ket have developed features that are very unusual and interesting, and they help us to understand the human mind and human language ability."

"We linguists should not be the focus of attention here," Vajda added. "What is important are the languages and especially the Native communities themselves." Vajda takes no credit for coming up with the Asian language connection. "People developed the beginnings of these ideas even 300 years ago, and in 1923 someone made the specific claim I am arguing for. My work builds on vocabulary comparisons made by other linguists in the late 1990s as well."


Posted by Amanda Graham – 6 July 2010; 5:54:23 PM – Permalink  

Arctic Biodiversity Trends 2010: Selected indicators of change report

Unique Arctic habitats for flora and fauna, including sea ice, tundra, lakes, and peatlands have been disappearing over recent decades, and some characteristic Arctic species have shown a decline. The changes in Arctic Biodiversity have global repercussions and are further creating challenges for people living in the Arctic.

The above statements are examples on the key findings describing changes in Arctic biodiversity that is presented in ‘The Arctic Biodiversity Trends – 2010: Selected Indicators of Change’, a new report recently launched synthesizing scientific findings on the status and trends for selected biodiversity in the Arctic issued by the Conservation of Arctic Flora and Fauna (CAFF) Working Group under the Arctic Council.

This report was recently launched at the Arctic Council Deputy Ministers’ meeting in Copenhagen on May 27. UNEP/GRID-Arendal contributed to the report through editing, graphic design and the production of all cartographics.

Download the full report. (23 mb)

Maps and Graphics from the report are available in:
GRID-Arendal Maps & Graphics Library


Posted by Amanda Graham – 13 June 2010; 1:02:48 PM – Permalink  

Shift in Gulf stream could be deadly

(Lillian Rizzo/The Ticker, 10 May 2010) -- An asteroid might not have been the reason for the dinosaurs’ extinction. New research by Dr. Gregory Price of Plymouth University, who has been studying fossils and minerals from Arctic Svalbard, shows that a change in the Atlantic Gulf Stream may have led to the wipe out of dinosaurs.

“World’s seas plummeted 9 degrees Celsius from 13 degrees Celsius to just 4 degrees Celsius around 137 million years ago,” according to the dailymail.co.uk. The findings were published in the newspaper on April 23 when Price spoke to the publication. Price and Dr. Elizabeth Nunn of Johannes Gutenburg Universitat in Mainz, Germany, have been studying in the Arctic Svalbard since 2005.  ... During the Cretaceous period, the area was filled with dinosaurs and had warm, shallow seas and swamps. While scientists have long attributed the extinction of the dinosaurs to an asteroid or comet impact, this new research reveals that it was a series of environmental changes beginning with a drop in sea temperature in the Cretaceous period that led to extinction. The plunge in temperature is attributed to high carbon dioxide levels in the atmosphere that caused global warming, similar to the earth’s current situation now.

“The drop in temperatures may well have been caused by a change in ocean circulation, much like what is being predicted for the Gulf Stream,” said Price in The Daily Mail. “We believe dinosaurs were most likely to be cold-blooded creatures and would have needed the warmth to keep them alive. If they were unable to migrate south, they could have been wiped out.” Price and his staff brought the evidence back to Plymouth to be analyzed. There is evidence to suggest that this change in climate can occur again, except less abruptly. According to the Wood Hole Oceanographic Institution, “Abrupt regional cooling and gradual global warming can unfold simultaneously ... greenhouse warming is a destabilizing factor that makes abrupt climate change more probable.”


Posted by Amanda Graham – 13 May 2010; 10:22:49 AM – Permalink  

Asthma rates in Inuit below national average

(Arctic Institute of North America press release via EurekAlert, 3 May 2010) -- OTTAWA, ON - New research shows Inuit populations in the Canadian Arctic have asthma rates far below Aboriginal people in other parts of Canada, especially those in urban centres. The study, published recently in the International Journal of Circumpolar Health, says reported cases of asthma in Inuit children was 5%, compared to 12% for all other Aboriginal groups. In Inuit adults, 5.4% of respondents had been diagnosed with asthma, compared to the national average of 11%.

Eric Crighton, lead author of the paper and geography professor at the University of Ottawa, says while it's not unusual to see lower rates of asthma in rural areas, that doesn't always mean rural residents are healthier than their urban cousins. While there is less air pollution in rural regions than in cities, in most other determinants of health – such as income, education, housing and the availability of health care - the North scores extremely low.

"It's my personal opinion ... that it's the limited access to health care that explains this finding. Aboriginal populations are heavily underserved (by health care) all across Canada, but in the North it's a bit more extreme," says Crighton, adding "The biggest determinant of doctor reported asthma is whether you've been to the doctor." The study is based on an analysis of data in Statistics Canada's 2001 Aboriginal People's Survey. A total of 60,500 adults in northern and southern Canada were surveyed. A child and youth questionnaire was administered to 34,495 respondents (parent, grandparents, etc.).


Posted by Amanda Graham – 4 May 2010; 1:43:44 AM – Permalink  

Inuit preschoolers show changing patterns of growth

(Ruth Klinkhammer/AINA via Medical News Today, 20 April 2010) -- Inuit preschoolers in Nunavut are as tall as their U.S. counterparts but they're also heavier, according to a new study published in the online edition of the International Journal of Circumpolar Health. This represents a remarkable change from previous work showing Inuit infants began life with equivalent birth lengths, but were falling behind by the time they were six months old.

"This is in many ways a good news story," says Dr. Tracey Galloway, lead author and a Post-doctoral Fellow at the University of Toronto's Dalla Lana School of Public Health. "Height reflects overall health status over a lifetime and over generations."

Unlike weight, which can fluctuate quickly, it takes decades for changes in health to be reflected in the height of a population. Factors influencing height include nutrition of the child, maternal health and diet, and infectious disease rates. However, says Galloway, it's impossible to know whether this trend will continue because school-aged children and youth have not been recently surveyed. The study of 26% of three- to five-year-olds in 16 Nunavut communities marks the first time data on the height and weight of preschoolers has been collected for Inuit populations living in the North.

The data are from the International Polar Year Nunavut Inuit Child Health Survey led by McGill University, the University of Toronto and territorial and community partners.


Posted by Amanda Graham – 29 April 2010; 1:45:30 AM – Permalink  

Research shows part of Alaska inundated by ancient megafloods

(University of Washington press release via EurekAlert, 28 April 2010) -- New research indicates that one of the largest fresh-water floods in Earth's history happened about 17,000 years ago and inundated a large area of Alaska that is now occupied in part by the city of Wasilla, widely known because of the 2008 presidential campaign. The event was one of at least four "megafloods" as Glacial Lake Atna breached ice dams and discharged water. The lake covered more than 3,500 square miles in the Copper River Basin northeast of Anchorage and Wasilla.

The megaflood that covered the Wasilla region released as much as 1,400 cubic kilometers, or 336 cubic miles, of water, enough to cover an area the size of Washington, D.C., to a depth of nearly 5 miles. That water volume drained from the lake in about a week and, at such great velocity, formed dunes higher than 110 feet, with at least a half-mile between crests. The dunes appear on topographical maps but today are covered by roads, buildings and other development.

"Your mind doesn't get around dunes of that size. Obviously the water had to be very deep to form them," said Michael Wiedmer, an Anchorage native who is pursuing graduate studies in forest resources at the University of Washington.

Wiedmer is the lead author of a paper describing the Wasilla-area megaflood, published in the May edition of the journal Quaternary Research. Co-authors are David R. Montgomery and Alan Gillespie, UW professors of Earth and space sciences, and Harvey Greenberg, a computer specialist in that department.

By definition, a megaflood has a flow of at least 1 million cubic meters of water per second (a cubic meter is about 264 gallons). The largest known fresh-water flood, at about 17 million cubic meters per second, originated in Glacial Lake Missoula in Montana and was one of a series of cataclysmic floods that formed the Channeled Scablands of eastern Washington. The megaflood from Glacial Lake Atna down what is now the Matanuska River to the Wasilla region might have had a flow of about 3 million cubic meters per second. Another suspected Atna megaflood along a different course to the Wasilla region, down the Susitna River, might have had a flow of about 11 million cubic meters per second. The researchers also found evidence for two smaller Atna megafloods, down the Tok and Copper rivers.


Posted by Amanda Graham – 29 April 2010; 1:41:58 AM – Permalink  

Warming soil releases more greenhouse gas

(Randy Shore/Vancouver Sun, 19 April 2010) -- Warming soils in Canada's North are releasing a vast store of carbon that has been inert for millennia, which could further accelerate the rate of climate change, according to the author of a new study published in the journal Nature. Field work conducted in Canada by the study's co-author Ben Bond-Lamberty suggests that the release of carbon in the soils of the world's tundra and northern boreal forests — about one third of all terrestrial carbon — is already underway, and he says soils all over the world are releasing more carbon dioxide as temperatures rise.

Bond-Lamberty and co-author Allison Thomson at Maryland's Joint Global Change Research Institute analysed data from 439 studies on soil respiration conducted in 1,434 locations in every corner of the world and found that plant growth, decomposition and microbial activity in the soil release about 98 billion tonnes of CO2 into the atmosphere every year, about 10 times the amount that humans release by burning fossil fuels, he said. That phenomenon by itself is not worrisome because soil has always released CO2 as part of a complex carbon cycle in which released carbon is absorbed by the world's oceans and growing plants in equilibrium.

"It's not surprising that higher temperatures have given rise to greater soil respiration," said Bond-Lamberty. "That's just basic science." But the amount of carbon being released by soils has increased by .01 per cent a year over the past 20 years as the world's temperature has increased and may be liberating carbon that has been stored in peat bogs, boreal forests and frozen soils for thousands of years. The danger is that the release of so-called "old carbon" could create a loop in which rising temperatures lead to the release of more carbon, which in turn raises the world's temperature, leading to accelerated carbon release, Thomson told The Sun. Canada's Arctic is one of the world's largest deposits of old carbon.


Posted by Amanda Graham – 22 April 2010; 2:13:19 PM – Permalink  

Report: March was Earth’s warmest on record

(USAToday, 16 April 2010) -- Although a large chunk of the USA didn't get in on the warmth in March, the rest of the world sure did. March was the warmest March ever recorded worldwide, the National Climatic Data Center (NCDC) reported Thursday. NCDC records go back to 1880. Another source, the University of Alabama-Huntsville, also reported that March 2010 was the warmest March since their climate records began in 1979.

According to the climate center, the combined global land and ocean average surface temperature in March was 56.3 degrees, which is 1.39 degrees above the 20th-century average of 54.9 degrees. Additionally, the worldwide ocean surface temperature was the highest for any March on record -- 1.01 degree above the 20th century average of 60.7 degrees. This was the 34th consecutive March with global land and ocean temperatures above the 20th century average.

The warmth in northern Canada and the Arctic was also noteworthy. Temperatures there soared to as much as 15 degrees above average for the month, the University of Alabama-Huntsville noted. The UAH dataset uses satellite measurements of temperatures from the surface up to about five miles in altitude.

"We have seen similar large anomalies on a month-to-month basis in the Arctic during the cold months (Dec. - March) in the past," noted climatologist John Christy of the University of Alabama-Huntsville. "This particular case is interesting because it persisted somewhere in the Arctic for four months."


Posted by Amanda Graham – 18 April 2010; 11:26:08 AM – Permalink  

Hudson Bay belugas focus of 2 studies

(CBC News, 12 April 2010) -- Federal fisheries scientists have been studying beluga whales in Hudson Bay, where changes to sea ice may have led to dropping mercury levels in some female whales but an emerging threat from another whale species. Although killer whales have been spotted in Hudson Bay since the 1950s, people in area communities have reported seeing more of them in recent years, said Steve Ferguson, a research scientist with the federal Department of Fisheries and Oceans. Ferguson, who works in the department's Arctic aquatic research division in Winnipeg, said he is analyzing hormone levels from beluga whale samples to determine how the belugas are reacting to the rising killer-whale threat.

"The indication is that the killer whales are there a little longer, now there's less sea ice, and maybe they're doing a little more attacking on the beluga," Ferguson told CBC News. "We're taking samples from them [belugas] to see if they're finding it more stressful recently, trying to live with killer whales around that are trying to kill them and eat them." Ferguson's research complements work being done by fellow DFO research scientist Gary Stern, who has found mercury contaminant levels have gone down in female beluga whales in Hudson Bay.

Stern found that methyl mercury levels in the muscle tissue of female beluga whales harvested in Arviat, Nunavut, have dropped by 32 per cent between 1984 and 2008. Longer ice-free periods on Hudson Bay could be affecting what and where the whales are eating, as the female belugas may be eating less contaminated prey that are found in offshore areas, Stern said.


Posted by Amanda Graham – 15 April 2010; 8:24:44 AM – Permalink  

Scientists turn to Inuit traditions to collect data on Arctic weather

(Thandi Fletcher/Canwest News Service via The Gazette, 11 April 2010) -- OTTAWA - Using traditional Inuit weather knowledge passed down through generations, environmental scientists have uncovered new data on Arctic climate change. In a study appearing this month in the journal Global Environmental Change, researchers working closely with Inuit elders were able to "zero in on what we'd been hearing from the Inuit people for a number of years," said Elizabeth Weatherhead, chief author of the study and environmental scientist at the University of Colorado at Boulder.

Since the early 1990s, Inuit hunters and elders have been noticing increasingly unpredictable weather patterns in their Arctic communities. But their observations didn't match up with scientific weather data. Scientific measurements suggested "weather persistence" around the world was actually becoming "more firm" with less variation, said Weatherhead. "When we have warm spells or cold spells, they last a few days, not three weeks non-stop," she explained. That time cycle is shifting on a global scale, she said, with spells now lasting longer than before. But Inuit people said the opposite was happening in their part of the world — that Arctic weather was behaving unpredictably. "[Inuit people] were identifying these changes in the weather and identifying how important it was, long before scientists realized, 'Hey, this is happening,'" said Weatherhead. Until now, scientific studies of climate change focused mainly on mean temperatures, according to the study's researchers. ...

The researchers are still unsure as to what is causing Arctic weather unpredictability, but a few theories have been put forward. One of those is climate change, Weatherhead said, "but it's not clear yet if this is (climate change) driven by greenhouse gases." Mead Treadwell, chair of the U.S. Arctic Research Commission, said he believes a few factors, including wind patterns and more extreme temperatures, are playing a part in the thinning sea ice. "The biggest change I've seen is the withdrawal of sea ice," he said. ... Weatherhead said her team's work with Inuit elders demonstrates how important it can be for scientists to combine their methods with traditional, indigenous knowledge.


Posted by Amanda Graham – 12 April 2010; 12:00:08 PM – Permalink  

New narwhal survey boosts population estimate

(CBC News, 9 April 2010) -- The number of narwhal in Baffin Bay is estimated at more than twice the previous figure after a recent survey using new techniques, say scientists with the Department of Fisheries and Oceans. Previously estimated at between 20,000 and 30,000, the Baffin Bay population is now said to be more than 60,000. One of the new surveying techniques involves a formula to estimate the number of narwhal below the surface at any given time, says Pierre Richard, a research scientist with the Department of Fisheries and Ocean. Past surveys counted only whales on the ocean surface, not those beneath it, he said. For the most recent count, researchers attached trackers to more than a dozen whales. "We found that narwhal on average spent one-third of their time at the surface. So for every animal that you would see at the surface, there are another two below the surface," said Richard. ... The chair of the Hunters and Trappers Organization in Pond Inlet, Jayko Alooloo, says the new numbers are not a surprise. Still, he says there are fewer whales in certain places, such as Eclipse Sound. Alooloo says hunters worry that increased marine traffic, snowmobiles, and the placing of trackers on whales is causing narwhal to bypass former hunting zones.


Posted by Amanda Graham – 11 April 2010; 11:08:25 PM – Permalink  

Deep freeze caused by melting of ice sheet

(CBC News, 1 April 2010) -- The melting of a giant North American ice sheet 13,000 years ago caused the Gulf Stream to shut down and triggered rapid cooling on a global scale, suggests new research. The Big Freeze or Younger Dryas occurred suddenly when the world was just coming out of a glacial period. Temperatures were rising between 15,000 years ago and 13,000 years ago, when suddenly the trend reversed and glacial conditions returned for another 1,400 years. The cause, say scientists at the University of Sheffield, was a flood triggered by the melting of the Laurentide ice sheet, which covered much of North America. The flood caused fresh water to mix with salt water in the Arctic Ocean, causing more sea-ice to form and move into the North Atlantic, shutting down the Gulf Stream. With the Gulf Stream halted, warm water failed to circulate across the Atlantic, causing temperatures in Europe to plunge.

The Sheffield scientists are basing their findings on signs of erosion in sediments contained in cliff sections within the Mackenzie Delta. The delta lies at the end of the Mackenzie River where it enters the Beaufort Sea in Canada's Arctic. The researchers determined that this erosion could only have occurred if an enormous flood had occurred from the melting Laurentide ice sheet. "The combination of luminescence dating, landscape elevation models and sedimentary evidence allows an insight into what must have been one of the most catastrophic geological events in recent Earth's history," said Mark Bateman, one of the paper's authors, from the University of Sheffield's department of geography, in a release.

The research could shed light on what might happen if Arctic ice continues to melt, increasing the levels of fresh water in the North Atlantic. There is speculation the Gulf Stream could shut down once again, leading to massive cooling on a global scale. The paper is published in the April issue of Nature (doi:10.1038/464657a).


Posted by Amanda Graham – 7 April 2010; 11:52:21 AM – Permalink  

Stone Age Scandinavians unable to digest milk

(Uppsala University press release, 1 April 2010) -- The hunter-gatherers who inhabited the southern coast of Scandinavia 4,000 years ago were lactose intolerant. This has been shown by a new study carried out by researchers at Uppsala University and Stockholm University. The study, which has been published in the journal BMC Evolutionary Biology, supports the researchers' earlier conclusion that today's Scandinavians are not descended from the Stone Age people in question but from a group that arrived later.

"This group of hunter-gatherers differed significantly from modern Swedes in terms of the DNA sequence that we generally associate with a capacity to digest lactose into adulthood," says Anna Linderholm, formerly of the Archaeological Research Laboratory, Stockholm University, presently at University College Cork, Ireland. According to the researchers, two possible explanations exist for the DNA differences. "One possibility is that these differences are evidence of a powerful selection process, through which the Stone Age hunter-gatherers' genes were lost due to some significant advantage associated with the capacity to digest milk," says Anna Linderholm. "The other possibility is that we simply are not descended from this group of Stone Age people." The capacity to consume unprocessed milk into adulthood is regarded as having been of great significance for human prehistory.

"This capacity is closely associated with the transition from hunter-gatherer to agricultural societies," says Anders Götherström of the Department of Evolutionary Biology at Uppsala University. He serves as coordinator of LeCHE (Lactase persistence and the early Cultural History of Europe), an EU-funded research project focusing on the significance of milk for European prehistory." In the present case, we are inclined to believe that the findings are indicative of what we call "gene flow," in other words, migration to the region at some later time of some new group of people, with whom we are genetically similar," he says. "This accords with the results of previous studies." The researchers' current work involves investigating the genetic makeup of the earliest agriculturalists in Scandinavia, with an eye to potential answers to questions about our ancestors.


Posted by Amanda Graham – 5 April 2010; 12:49:05 PM – Permalink  

A river ran through it: Lake Agassiz drained northward

(University of Manitoba press release, 1 April 2010) -- A team of researchers have found evidence that climate change on a global scale took place about 13,000 years ago, caused by a flood of biblical proportions. Previous research had suggested that a massive outpouring of water from glacial Lake Agassiz in Canada may have travelled down the St. Lawrence eastward and out into the Atlantic Ocean, causing significant global climate change. But, writing in the journal Nature this week, geologists from England and Canada have discovered that the outflow likely went north into the Arctic Ocean instead. Lake Agassiz was a large body of water that covered much of what is now the Canadian prairies, created by the damming of northward drainage by the huge ice sheet that covered much of Canada at this time.

The team of geologists examined boulder gravel in the Athabasca River Valley just north of Fort McMurray, Alberta. This material was deposited when thousands of cubic kilometres of water from glacial Lake Agassiz rushed through the area many millennia ago. Most importantly, the dating of deposits related to this flood far downstream, near the mouth of the Mackenzie River, has established that this catastrophic flood occurred 13,000 years ago. This coincides with the start of a well-documented cooling period around the globe known as the Younger Dryas, which began a thousand-year-long cold spell. ...

“This new evidence adds to our view that the outburst flood from Lake Agassiz did lead to a change in ocean circulation and climate cooling,” explains research team member James Teller, geological sciences, University of Manitoba. “This may mean that the ice in the Arctic Ocean was forced out into the North Atlantic and helped change ocean circulation.”


Posted by Amanda Graham – 4 April 2010; 7:15:15 PM – Permalink  

Greenland ice sheet losing mass on northwest coast

(University of Colorado at Boulder press release via EurekAlert! 23 March 2010) -- Ice loss from the Greenland ice sheet, which has been increasing during the past decade over its southern region, is now moving up its northwest coast, according to a new international study. Led by the Denmark Technical Institute's National Space Institute in Copenhagen and involving the University of Colorado at Boulder, the study indicated the ice-loss acceleration began moving up the northwest coast of Greenland starting in late 2005.

The team drew their conclusions by comparing data from NASA's Gravity and Recovery Climate Experiment satellite system, or GRACE, with continuous GPS measurements made from long-term sites on bedrock on the edges of the ice sheet. The data from the GPS and GRACE provided the researchers with monthly averages of crustal uplift caused by ice-mass loss.

The team combined the uplift measured by GRACE over United Kingdom-sized chunks of Greenland while the GPS receivers monitor crustal uplift on scales of just tens of miles. "Our results show that the ice loss, which has been well documented over southern portions of Greenland, is now spreading up along the northwest coast," said Shfaqat Abbas Khan, lead author on a paper that will appear in Geophysical Research Letters. The team found that uplift rates near the Thule Air Base on Greenland's northwest coast rose by roughly 1.5 inches, or about 4 centimeters, from October 2005 to August 2009.

Although the low resolution of GRACE -- a swath of about 155 miles, or 250 kilometers across -- is not precise enough to pinpoint the source of the ice loss, the fact that the ice sheet is losing mass nearer to the ice sheet margins suggests the flows of Greenland outlet glaciers there are increasing in velocity, said the study authors.


Posted by Amanda Graham – 28 March 2010; 2:08:32 PM – Permalink  

Number of High Arctic animals declining

(CBC News, 18 March 2010) -- Animals in the Arctic have increased in number over the last 40 years, but populations closest to the North Pole are shrinking, a new international study says. The report, commissioned by the Circumpolar Biodiversity Monitoring Program (CBMP) and funded by the government of Canada, found that overall, the number of mammals, birds and fish in the Arctic has increased by 16 per cent since 1970. The Arctic Species Trend Index, released Wednesday at a conference in Miami, credited hunting restrictions in place for decades with the animals' recovery. The number of geese, for example, has doubled, and certain species of whale are also recovering. The biggest recovery was in the southernmost parts of the Arctic, where the number of animals was up 46 per cent from 1970 to 2004. In sharp contrast, though, is the High Arctic, the area closest to the North Pole. The number of animals dropped by 25 per cent in the same time period, while the number of caribou was down by about one-third."What we're seeing is that there's winners and losers with rapid changes in the Arctic," said Mike Gill, a Canadian government researcher and study co-author. Gill is also chair of the CBMP. Louise McRad of the Zoological Society of London said the decrease near the North Pole is most worrisome because the effects of climate change are most dramatic in that area and are expected to worsen. The pressure brought by the loss of sea ice will only increase, she said. Gill said there isn't enough evidence to blame climate change directly for the loss of animals, but it is "largely in line with what would be predicted with climate change."

Posted by Amanda Graham – 20 March 2010; 2:14:50 PM – Permalink  

High Arctic species on thin ice

(RedOrbit, 17 March 2010) -- A new assessment of the Arctic's biodiversity reports a 26 percent decline in species populations in the high Arctic. Populations of lemmings, caribou and red knot are some of the species that have experienced declines over the past 34 years, according to the first report from The Arctic Species Trend Index (ASTI), which provides crucial information on how the Arctic's ecosystems and wildlife are responding to environmental change. While some of these declines may be part of a natural cycle, there is concern that pressures such as climate change may be exacerbating natural cyclic declines.

In contrast, population levels of species living in the sub-Arctic and low Arctic are relatively stable and in some cases, increasing. Populations of marine mammals, including bowhead whales found in the low Arctic, may have benefited from the recent tightening of hunting laws. Some fish species have also experienced population increases in response to rising sea temperatures.

"Rapid changes to the Arctic's ecosystems will have consequences for the Arctic that will be felt globally. The Arctic is host to abundant and diverse wildlife populations, many of which migrate annually from all regions of the globe.

This region acts as a critical component in the Earth's physical, chemical, and biological regulatory system," says lead-author Louise McRae from the Zoological Society of London (ZSL). Data collected on migratory Arctic shorebirds show that their numbers have also decreased. Further research is now needed to determine whether this is the result of changes in the Arctic or at other stopover sites on their migration. ...

The findings of the first ASTI report will be presented at the 'State of the Arctic' Conference in Miami, USA. The full report will be available to download from www.asti.is on Wednesday March 17th, 2010.


Posted by Amanda Graham – 17 March 2010; 6:07:58 PM – Permalink  

Humans off hook for muskox decline

(Randy Boswell/Canwest News Service via The Gazette, 10 March 2010) -- Scientists studying DNA from ancient muskox bones collected in Canada and elsewhere around the world have ruled out prehistoric human hunters as the cause of a steep decline 12,000 years ago in populations of the iconic northern species, now restricted largely to Greenland and the Canadian Arctic islands.

An international team of 20 researchers from eight countries — including paleontologists from the Yukon government and the Canadian Museum of Nature in Ottawa — found that a warmer, wetter climate at the end of the last ice age was chiefly to blame for the disappearance of the shaggy beast from most of its traditional range across the planet's northern frontier. And while hunting in recent centuries has wiped out pockets of muskox in more southerly locales — including areas in mainland Canada around Hudson Bay — the Canadian North has been a crucial refuge for the animal over the millennia as it survived climate swings that doomed such other species as the woolly mammoth.

Yukon paleontologist Grant Zazula, co-author of the landmark study published in the journal Proceedings of the National Academy of Sciences, said yesterday that a 50,000-year record of muskox remains found at Yukon's Herschel Island was key to unravelling the history of the species. He said recent melting of the island's permafrost means that "tons of bones get washed up on the beach" — a priceless resource for international scientists studying the evolution of the muskox, a grazing cousin of cows and bison that once occupied the entire circumpolar world.


Posted by Amanda Graham – 10 March 2010; 5:42:17 PM – Permalink  

Site yields clues to evolution

(Randy Boswell/Canwest News Service, 5 March 2010) -- Scientists studying an ancient meteorite crash site in the Canadian Arctic have detected traces of microbes that point to the key role played by impact craters in the evolution of life on Earth and could help determine whether life once existed on Mars. The discovery — hailed by an 11-member team of researchers from Canada, Britain, the U.S. and Sweden as a scientific "first" — was made at Devon Island's famous Haughton Crater, a uniquely dry and desolate geological gem probed frequently by experts from NASA because of its Mars-like features.

"Meteorite impact craters have been proposed as possible sites to find microbial life on Mars, as they are a focus for heat and water circulation," the research team, including University of Western Ontario geologist Gordon Osinski, state in a summary of their findings. The researchers examined meteorite-shocked rocks from numerous sites throughout the 24-kilometre-wide crater and found telltale traces of sulphur left behind by heat-loving, "thermophilic" bacteria that moved into the crash site following the impact.

"Evidence of widespread microbial activity" in the Canadian crater, the team says, has "shown for the first time that a crater was pervasively colonized by microbes, and that colonization of over 20 cubic kilometres of impact rock was rapid, within 10,000 years after impact, while the rock was still warm."


Posted by Amanda Graham – 7 March 2010; 11:24:38 AM – Permalink  

International team sequences ancient polar bear mitochondrial genome

(Andrea Anderson/GenomeWeb News, 1 March 2010) -- NEW YORK - An international research team led by investigators at the University of Oslo's Natural History Museum has sequenced the mitochondrial genome of an ancient polar bear, finding new clues about polar bears' evolutionary history and relationship to brown bears. In a paper scheduled to appear online this week in the Proceedings of the National Academy of Sciences, researchers from Norway, Iceland, and the US used Roche 454 sequencing to sequence the complete mitochondrial genome from 110,000- and 130,000-year old polar bear remains found in Norway several years ago.

The findings suggest the ancient polar bear lived right around the time that the lineage leading to modern polar bears' divergence from the lineage of a closely related group of brown bears — called the ABC brown bears — found on Alaska's Admiralty, Baranof and Chichagof Islands.

"It's basically a transitional link between brown bears and polar bears," co-lead author Charlotte Lindqvist, an evolutionary biology researcher at the University of Buffalo who performed some of the work as a post-doctoral researcher at the University of Oslo Natural History Museum, told GenomeWeb Daily News. "It truly is between at least brown bears from the ABC islands and polar bears." Lindqvist and her co-workers isolated DNA from ancient polar bear remains found at the Poolepynten site in western Norway's Svalbard Archipelago in 2004. The jawbone and canine tooth found at that site represent a rare find, partly because of polar bears' sea ice environment.

"Because polar bears live on the ice, their dead remains fall to the bottom of the ocean or get scavenged," senior author Øystein Wiig, a polar bear expert at the University of Oslo Natural History Museum, said in a statement. "They don't get deposited in the sediments like other mammals."


Posted by Amanda Graham – 3 March 2010; 6:59:44 PM – Permalink