Category Archives: NLN Aurora Brief

NLN Aurora Brief – November 6, 2015

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Aurora Brief Volume 3, Number 4 of 7
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One the Sun

Flaring activity decreased markedly. Active region 2443 which created the large M3.7 flare yesterday lost delta spots, it’s now classified beta, and decreased in size. It only produced a single B-class flare. It’s seems to be a pattern recently that flaring activity slowly increases until there is a flare that releases a larger than pattern amount of energy then the source region settles. It is likely that there will be limited flaring activity for the next three days.

On Earth

We are awaiting the arrival of the CME from yesterday’s M-class flare. SWPC has extended the G1 watch into Sunday. Forecasters are predicting a 12 hours window of potential G1 storming starting in the last 6 hours of the Saturday period. For Europe, that’s a start time of just before midnight, for those in N. America, the storm could already be rolling as the Sun sets.

NLN's 3-day prediction infographic shows G1 Aurora storming 11/7 and 11/8
NLN’s 3-day prediction infographic shows G1 Aurora storming 11/7 and 11/8

Initial indications are also that this is a slow moving CME, so it may be a little later than forecast. Case in point, the porton levels measured at ACE have not started increasing yet. In a typical Earth-directed CME, we’d see the readings rising by now. Keep an eye on this data as it is the first the next sign that a solar storm is headed towards Earth. Here is a link to the source of the 3-day EPAM image.

Proton levels graph from ACE EPAM doesn't show activity yet
Proton levels have not started rising yet, look for this as the next sign the CME is approaching Earth

Happy Hunting!

NLN Aurora Brief – November 5, 2015

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Aurora Brief Volume 3, Number 3 of 7
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One the Sun

Flaring activity increased today with three M-class flares including a long-duration M3.72 flare from AR 2443 that will impact geomagnetic activity at Earth this weekend. Departing AR 2445 produced an M2 and and M1 flare as it weakened and lost it’s magnetic complexity. Neither flare produced an earth-directed CME. Other regions on the sun were quiet.

Profile of the long duration M3.72 flare that is responsible for Earth-directed CME
Profile of the long duration M3.72 flare that is responsible for Earth-directed CME

The M-class flare from AR2443 was responsible for imagery that will be catnip to aurora hunters. The flare happened almost exactly at the center of the disk, which means that almost any CME will be directed towards Earth. LASCO images showed a clear partial halo CME. Analysis is still ongoing to determine the speed of the ejecta to estimate when it will arrive at Earth. Initial esitmates and WSA-Enlil model runs indicate that it will likely be geoeffective on Saturday Nov 7. The 3-day forecast page will be updated to show potential timing with tomorrow morning’s update (around 7:30am), so check back then.

Coronal Dimming from M3.72 flare
Dimming indicates that there is material between the camera and the coronal – a signature of a CME launch

On Earth

Aurora and elevated KP continued for most of the day with 5 three-hour periods experiencing G1 storming. Bz was variable, but occiassionally weakly south for long enough for additional 20 minute spurts of activity. Here are the recorded KP values:

KP values recap from Nov 3-4 2015 solar storm
KP values recap from Nov 3-4 2015 solar storm

There were a few really good aurora pictures, but the timing, duration, and weakness of the storm proved frustrating for many hunters. If you were lucky enough to be in the right place at the right time to see aurora, you are amoung the lucky few. Some of our favorite tweets:

Happy Hunting!

NLN Aurora Brief – November 4, 2015

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Aurora Brief Volume 3, Number 2 of 7
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Aurora Storm Update

Finally – Strong solar winds and G1 storming arrived as the impact from the coronal hole was felt. Solar wind speeds increased in a stepped pattern with several shocks – first to 500km/s, then to 650km/s then peaking around 759 km/s. Winds have been in the 700-760 km/s range since. The Bz has been shifting back and forth between negative and positive which has lead to several short bouts of aurora. Some aurora hunters have been lucky, while others, just a couple hundred miles away or looking at a slightly different time have seen nothing. While there have been periods of G2 storming, the official record of 3-hour averages will only show G1 activity from this storm (so far). Here’s an image of the Geomagnetic activity over the last couple days.

SWPC KP history for Nov 3 aurora storm from coronal hole
SWPC KP history for Nov 3 aurora storm from coronal hole

There is still a chance for more activity over the next 6-12 hours, and solar winds are expected to remain elevated for the next 72 hours. Any disturbances on the wind stream could lead to a spike in activity – so keep an eye on the KP!

Speaking of disturbances, those could come from flares originating in the two beta-delta active regions. Both AR2443 and AR2445 are in the Earth stike zone and are displaying magnetic activity that could lead to M-class flaring. If they do generate a fast moving CME, it could catch up to the wind speed and create a show.

Here’s a great Aurora image from Kiruna, Sweden by Mia Stålnacke

Happy Hunting!