September 29, 2010

What’s Happening With The Northern Lights?

The aurora borealis, or Northern Lights, have dwindled in the last five years, becoming more rare than at any other time in the last hundred years, said the Finnish Meteorological Institute on Tuesday.

The Northern Lights typically follow an eleven-year "solar cycle," in which frequency of the phenomena increases to a maximum point then begins to taper off toward a minimum and then repeats the cycle.

The last solar minimum occurred in 2008, but seems to have continued "on and on and on," researcher Noora Partamies told AFP.

In the past half a year activity has picked up, but "we don't really know whether we're coming out of this minimum," Partamies added.

The Northern Lights are triggered by solar wind particles crashing into earth's upper atmosphere where they are drawn to the magnetic poles, wreaking havoc on electrons in the ionosphere and magnetosphere. The aurora borealis emit a blaze of colored patterns along the northern skies.

The dimming of the Northern lights is a signal that activity on the sun, which causes solar winds, is also quieting down.

A network of modern observation stations will help researchers, for the first time, to see what happens to the solar cycle when it becomes as badly disrupted as it is now. "We're waiting to see what happens, is the next maximum going to be on time, is it going to be late, is it going to be huge?" Partamies said.

During the solar cycle's peak in 2003, a Norway station located near the North Pole, showed the Northern Lights were visible almost every single night of the Auroral season, excluding nightless summer months.

That figure has dropped to less than 50 percent, while a station in southern Finland, has only registered two to five instances annually for the past few years.

Image Courtesy NASA


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