NLN Aurora Brief – October 25, 2015

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Aurora Brief Number 6 of 14
Previous Brief: NLN Aurora Briefs – October 24, 2015
Next Brief: NLN Aurora Briefs – October 26, 2015
Today on the Sun:

Once again, on the surface of the Sun activity is low and decreasing. Active region 2434 was the most active region but only produced three C1 flares and displayed evidence of decay as it rotated around the western limb. AR 2436 continued to decreased in size, but showed growth in it’s trailer spots and it’s total spot count increased slightly.

A G1 geomagnetic watch continues to be in effect for today. The expected CME arrived late in the October 24th period as expected. While it appears the majority of the CME passed Earth to the West (behind) and South of Earth, the shock was evident on EPAM and in solar wind data. When it arrived it was strong enough to produce aurora, however the orientation of the cloud so far has been North-pointed so far. The expected increase in KP will not materialize unless the Bz shifts to the south. Keep an eye on it, but this storm is likely not going produce a major storm. In these images, see the EPAM at the time the CME shock arrives and the solar wind data as visualized by

EPAM shows arrival of CME shock
EPAM shows arrival of CME shock
Solar wind data at the time of arrival of CME
Solar wind data at the time of arrival of CME

This day in 2003:

Active regions 484 and 486 continue to be the most magnetically complex regions, but the activity they produced decreased to moderate with 4 M-class flares. Similar to today’s activity, there were CME passages, but the Bz component of the magnetic field remained north – so there were few reports of aurora. A 10-degree filament lifted off the surface of the Sun, it produced a non-earth directed CME. The probability of x-class flares was set to 40% and M-class flares to 85%. The next days’s activity would prove the flare predictions accurate.

Happy hunting!