(Tim Mowry/Fairbanks Daily News-Miner, 23 February 2009) -- FAIRBANKS — Ester photographer LeRoy Zimmerman made the switch to digital cameras this year to better capture the phenomenon known as the aurora borealis. Now he just needs some aurora to work with. “There’s nothing; it’s really disappointing,” Zimmerman said. “I’ve got my digital camera. I’m ready. Let’s go.” Zimmerman isn’t the only one wondering where the aurora borealis, commonly referred to as northern lights, are this winter. The Interior’s normal wintertime light show has been noticeably absent this winter. “I talk to people in town and everybody who knows what I do asks me, ‘Where is the aurora? What’s happening?’” said Dirk Lummerzheim, a research professor who studies the aurora borealis for the Geophysical Institute at the University of Alaska Fairbanks. It’s a legitimate question, and Lummerzheim has the answer. “We are at the solar minimum,” the UAF professor said. “When solar activity dies down like this, the aurora activity also diminishes in the north.” Aurora borealis, a curtain-like, luminous glow in the upper atmosphere, is caused when energy particles from the sun collide with the Earth’s magnetic field. Solar activity runs on a 22-year cycle — 11 positive years and 11 negative years. The cycle is at the bottom of the negative cycle, Lummerzheim said. This is the second winter in a row the aurora has been “quiet,” as Lummerzheim put it. Normally, the low in the solar cycle only lasts about a year, he said. Lummerzheim described the current solar minimum as “very long, very deep.” “I think the last time we had a minimum this low was early in the 20th century,” he said. “If you look at the sun, I think we’ve had one sunspot group this year,” Lummerzheim said. “When we get into the maximum phase, it has lots of sunspots and all kinds of things going on all the time. There are big explosions.” Aurora scholar Neal Brown, who directs UAF’s Alaska Space Grant Program, said the low in the current solar cycle is the most dramatic he has witnessed during his time in Fairbanks.
Posted 23 February 2009; 2:57:28 PM. Permalink