September 11, 2015 Aurora
Mahtomedi, Minnesota
I was down in the Twin Cities overnight during G3 geomagnetic storming conditions due to the combination of a high speed solar wind stream and a coronal mass ejection (CME) sweeping by Earth. This started some auroras as Bz went briefly south to near -15 nT, but the show was surprisingly weak given the southward deviation in magnetic field.
Nevertheless, I could barely see the auroras among the city light glow in the northern suburbs of the Twin Cities. A look to the southwest revealed that it was much brighter there, and that would have prevented me from seeing the auroras altogether.
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| Weak auroras over White Bear Lake. |
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| City light haze to the southwest. ISO 800, f1.6, 8 seconds. This normally would have been a rather dark picture away from the city lights. |