M-Class Flare Promts G1 Aurora Storm Watch For November 11, 2015

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An coronal mass ejection (CME) that resulted from a surprise M3.95 solar flare launched a from the Sun on Monday has prompted the NOAA Space Weather Prediction Center (SWPC) to issue a G1 geomagnetic storm watch for Veterans day and November 12th. As the CME arrives at Earth, aurora hunters may be treated to a display of northern lights further south than normal.

NLN Aurora cast clock from SWPC 3-day forecast shows 15 hours of G1 storming forecast.
NLN AuroraCast clock from SWPC 3-day forecast shows 15 hours of G1 storming forecast.

A G1 storm watch means that the KP, a global scale of geomagnetic and aurora activity, may reach five out on it’s 0-9 range. As the KP rises higher, aurora borealis can be seen at lower latitudes. KP=5 indicates that the lights can be seen throughout Canada, along the northern boarder of the Continental United States, Northern Europe, and southern New Zealand.

KP is notoriously hard to predict, about 50% of the time a G1 watch is in effect, the KP does not actually rise to that level, but a G1 watch also means that the KP could easily rise higher than five. If you want to know the current KP readings, your best option is to monitor live KP trackers, such as Northern Lights Now’s current live KP chart, which give an accurate KP forecast 35-70 minutes in advance.

The flare that launched the CME was a surprise. It launched from active region 2449, which had a Beta magnetic structure. Typically, active regions need to have a “delta” sunspot in their group and be classified Beta-Delta or Beta-Delta-Gamma. Nonetheless, the solar flare that launched was spectactular. Here is an animated gif of the solar region while the flare was happening. Note that this is a zoomed in image, but that the several Earths could fit in the flare area.

The M3.95 flare from November 9 from SDO imagery
The M3.95 flare from November 9 from SDO imagery over a 12 hour period

When flares eruptions are long duration, like this one was, they can generate CMEs. A coronal mass ejection is a cloud of solar plasma that shoots from the Sun. When a CME is moving towards Earth, it typically arrives between 2 and 4 days later. As the plasma cloud passes earth, it disrupts the magenetosphere and sends charged particles into our upper atmosphere. It is the interaction of those particles with the gases in out atmosphere that cause the dancing northern lights. Don’t worry though! This storm won’t be strong enough to have any impact at Earth’s surface – just enjoy the show!

Happy Hunting

NLN Aurora Brief – November 9, 2015

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Aurora Brief Volume 3, Number 7 of 7
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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.

On Earth

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:

AIA 211 image showing Coronal hole responsible for November 8, 2015 G1 storming
AIA 211 image showing Coronal hole responsible for November 8, 2015 G1 storming

And a tweet showing aurora from November 8:

Happy Hunting!

NLN Aurora Brief – November 8, 2015

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On Earth

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.

Happy Hunting!