Despite a lull in solar activity, July began with a beautiful display of color over Calgary, Alberta.
Harlan Thomas photographed the sudden apparition of unexpected green auroras and silver noctilucent clouds.
Forecasts said noctilucent clouds would be abundant over North America on June 1, 2016. At around 12:30am, the noctilucent clouds had appeared, and they were accompanied by some green auroras as well.
The auroras were a surprise. There were no sunspots, no solar flares, and no CMEs on June 30th, yet skies turned green anyway.
So how is that possible?
Earth passed through a region of space filled with negative-polarity magnetic fields. Such fields can open a crack in Earth’s magnetosphere. Solar wind pours in and sparks auroras. And thus no sunspots are required.