Tag Archives: SDO

Several Interesting Features on the Sun As March Closes

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Update: 00:30 3/31/2016 GMT (8:30 EST)

SWPC has now issued a G1 geomagnetic storm watch for Saturday April 2nd.

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Northern Lights Now – As March draws to a close, there are a couple areas on the Solar disk with notable activity. On Sunday, a stunning solar prominence on the East limb produced a show in SDO imagery. Today, an active region that grew from alpha to beta and is now pointed straight at Earth and located between two coronal holes. Both coronal holes are in negative polarity regions and are related to coronal holes that produced negative Bz and aurora during their previous rotation. It’s possible this could happen again, but likley to a lesser degree on the current rotation.

A prominence

A solar prominence happens when a large area of gas and charged particles lifts off the Sun into the corona. Prominences are visible in the 304 Angstrom images available on the SDO website. When they happen on the limb they are spectacular, as the dark sky of space acts as a backdrop to the heated gasses lift off the surface. Here’s an animated GIF of images of the prominence as it erupted on Sunday on the east limb over a 12 hour period.

A prominence lifts off the East limb  in timelapse animated GIF of AIA 304 from SDO
A prominence lifts off the East limb in timelapse animated GIF of AIA 304 from SDO

It is unlikely this feature will have any impact on Earth. If it did produce a CME during the eruption, it would be well to the East of the Earth-Sun line.

A Growing Beta Active Region

Active Region 2526 has been increasing in size (from 120MH to 200MH) as it rotates toward center disk. Tonight, SWPC upgraded the magnetic classification from Alpha to Beta. The changes to the region are minor but do increase the probability of flare activity slightly. Thus far, the active region has not produced much flare activity, but keep an eye on it, this could change.

Active Region 2526, now Classified Beta, in magnetogram
Active Region 2526, now Classified Beta, in magnetogram

A Pair of Coronal Holes

The most promising solar feature for aurora hunters is the coronal hole that was pointed at Earth yesterday. On it’s previous pass, this coronal hole was a complex of three separate holes and lead to a prolonged period of enhanced solar wind, several periods of south-oriented Bz and a phenomenal display of Aurora. The coronal hole structure has degraded since the last rotation and is now comprised of a pair of medium sized coronal holes. Until today, when the second hole emerged to the NE of the first, this single coronal hole might have produced a short period of elevated solar wind. Now that it is a pair, Earth could experience couple days of slightly elevated soalr wind. Even better news for aurora hunters is that active region 2526 is directly between these two coronal holes, so if it does flare and produce a CME, the plasma will be accelerated by the elevated wind speed. Again, these are worth keeping an eye on the next couple days.

Two coronal hole in this AIA 211 image with active region 2526 directly between them
Two coronal hole in this AIA 211 image with active region 2526 directly between them

Happy Hunting!

G2 Storm Conditions Possible on March 11

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Norther Lights Now – The official forecast from the Space Weather Prediction Center (SWPC) is calling for a couple periods of G1 and G2 aurora late on March 11, 2013:

Brief Period of G2 storming predicted for the  second half of March 11
Brief Period of G2 storming predicted for the second half of March 11

This is due to a small solar storm with a period of dimming combined with high speed solar wind eminating from a coronal hole. This is something of a suprise storm. The CME is narrow and the coronal hole is small so this is a low confidence forecast. As such, SWPC has not even issued a geomagnetic storm watch for today.

Coronal hole in the southern hemisphere, center disk will make for high speed solar wind on 3/11
Coronal hole in the southern hemisphere, center disk will make for high speed solar wind on 3/11

Further, it’s possible that the expected solar storm has already passed Earth. There was a brief period of G1 storming mid-day on March 11. This may have been the expected activity. Space Weather forecasters are still analyzing this storm.

There was a period of G1 storming in the first half of March 11
There was a period of G1 storming in the first half of March 11

Happy Hunting

Valentine’s Day G1 Aurora Watch Posted By SWPC

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Northern Lights Now – The Space Weather Prediction Center (SWCP) has posted a G1 geomagnetic storm watch indicating probable KP>5 for February 14th and 15th 2016. This means aurora borealis may be visible in mid latitudes. The timing indicates that Europe and North America will be best positioned for a show Valentine’s Day Evening. As always with storm watches like this, the actual storming period could arrive up to 6 hours before or after the predicted arrival. Now is the time to start monitoring developments in space weather and cloudcover forecasts to know if the northern lights will be visible to you and planning your night our aurora hunting.

Update: Feb 13: NLN is now posting live updates for this storm.

As of the time the watch was posted, Earth is expected to see KP levels at 5 or above from 21:00GMT on 2/14 through 06:00GMT on 2/15 (4:00m-1:00am EST). There may be up to 12 hours past the arrival of the storm where KP may still be in the KP=4+ range. The forecast may be updated as more data comes in, so keep an eye on the NLN 3-day AuroraCast page for updates over the next couple days. As of this post, here is the current AuroraCast:

NLN 3-day Aurora cast for days 2 and 3 shows KP=5 possible on February 14 and 15, 2016
NLN 3-day Aurora cast for days 2 and 3 shows KP=5 possible on February 14 and 15, 2016

This storm is caused by a Coronal Mass Ejection (CME) that erupted from the surface of the Sun during a C8.92 flare on February 11th. You can see that eruption in the northwest (upper left) quadrant of the solar disk in this timelapse captured from the Solar Dynamic Observatory Satellite. SDO is a camera trained on the Sun that takes thousands of high resolution images per day in multiple different wavelengths. As the Flare erupts over the course of almost 90 minutes, you can see a dark area moving up and away from the eruption location. This dark area, several times the size of Earth, is the CME. It appears as dimming because the ejected plasma is cooler than the Sun and located between the Sun and the camera on the SDO sattelite.

C8.92 Solar flare launches from Active Region 2497 on 2/11. The CME may produce Aurora on 2/14 and 2/15

Normally, CME’s take 2-3 days to arrive at Earth after an eruption. The eruption is moving much slower and will take 3-4 days to arrive. That could mean that it will arrive with lower solar wind speed, which would dampen chances for a great show. But it also means that as it arrives, it may put on a longer show. Stay tuned for updates!

Happy Hunting