[MIham] NEGATIVE MAGNETIC FIELDS SPARK AURORAS

[Frank]

NEGATIVE MAGNETIC FIELDS SPARK AURORAS: On Saturday, April 30th, Earth 
entered a region of space filled with negative-polarity magnetic fields. 
This sparked an outburst of springtime auroras around the Arctic Circle.

Todd Salat photographed the display from the shore of Lake Louise, 
Alaska. "I took this picture during the darkest part of the night on 
April 30, 2016, around 1:25 am," he says. "The auroras were reflecting 
beautifully from the surface of the lake during my self-portrait."

The orange glow in Salat's picture is caused by the Midnight Sun, just 
below the horizon. At this time of year, auroras have a hard time being 
seen at Arctic latitudes because of the persistent twilight. 
Nevertheless, Salat got a good shot.

"I keep thinking this is the end of the aurora season for high northern 
latitudes," he says, "but then I think of that infamous 1973 quote from 
baseball legend Yogi Berra, 'It ain't over till it's over.'"

Indeed, more auroras could be in the offing. NOAA forecasters estimate a 
40% to 50% chance of G1-class geomagnetic storms on April 30th-May 1st 
as Earth moves into a weekend solar wind stream.