Aurora Brief Volume 3, Number 7 of 7
Other Briefs: Previous Brief — Next Brief (link available when active period is imminent)
On the Sun
The largest flare of the period was reached B5 X-ray flux from AR2449 – indicating very low activity. The region showed the slightest of growth, maintaining its size and magnetic complexity while adding 2 sunspots. Other regions were quiet. The only hint that there may be activity is a small filament between AR 2448 and AR 2451. Old AR 2425 is due to return to the eastern limb at S13 in the next couple days. Flare activity is likely to be low.
The high speed wind stream from the large northern hemisphere coronal hole arrived at Earth bringing brief periods of G1 storming. Some aurora hunters in europe were able to catch glimpses of the northern lights on their horizons. The activity from this high speed stream is expected to wane over the course of the day – with a slight chance for another G1 active period. Looking to the 3-5 day outlook, geomagnetic activity will likely remain low.
Here’s an image of the coronal hole currently influencing Earth’s magnetophere taken from November 7 in AIA 211 (purple) wavelength:
The CME from the M3.7 flare traveled faster than models predicted, so arrived a earlier than forecast. It arrived with a consistent north oriented Bz component. But at 02:00, it settle into steady south (-7 to -11 range) orientation. Regular readers know steady south is what aurora hunters hope for. It produced a 12 hour period of G1 and G2 storming. Northern lights sighting reports streamed in on Twitter. Here is a video montage of some of our favorite images that came in on Twitter:
There is a slight chance for additional storming late in the 11/8 period due to the high speed wind from yet another coronal hole. This had previously been forecast to produce G1 storming as it arrived with the tail end of yesterday’s geomagnetic storming. However, since yesterday’s storm was early the effects of the coronal hole are expected less conducive to Aurora
On the Sun
As new active region 2449 continues to rotate into view it appears to have a beta magnetic structure. It produced the largest flare of the period – a C4 flare at 18:11. AR2449 increased in size a small amount in the last 24 hours. It has a very slight chance of producing M-class flaring. Other regions on the disk remain quiet.
New Active region 2449 is rotating into view on the eastern limb. It is still to early to tell for sure what magnetic classification is should have yet. It will be more clear for tomorrow’s Aurora Brief. This region produced a a C4.48 flare, the largest flare of the period. The flare did not produce and Earth-directed CME. All other regions remained the same, or decreased in magnetic complexity.
At the end of the period, a CME shock was recorded hitting the ACE satellite. The shock registered on ground based magnetometers about 45 minutes later. KP readings for the end of the period were as high as 4.67. Here are two aurora pics that came in on Twitter just as the aurora was getting going.
So far this solar storm’s Bz component has again been North pointed. So once again, storming levels will be limited. This could shift to South at any time, so don’t give up hope yet!
The continues to be a G1 watch in effect for both November 7 and November 8 as the CME from the M3.7 flare is expected to arrive. It is unclear at this point whether the shock the arrived just now was that expected CME, or if there will be another shock as main CME arrives. For now, aurora hunters can keep their fingers crossed that the second storm will arrive later today and that it will have a more favorable Bz component.