Four M-class and an X2.2 solar flare from sunspot region 2297

woensdag 11 maart 2015 18:59 UTC

Major X2.2 solar #flare - Follow live on http://t.co/XHATH0OOfT pic.twitter.com/CVRbnUxQfb

— SpaceWeatherLive (@_SpaceWeather_) 11 maart 2015

Let's start with the good news first: a coronal mass ejection has likely been launched. Difference imagery from SDO shows that it was an eruptive event but those with good eyes can see that the bulk of the ejecta looks to be heading east and away for Earth. There is still a good chance that part of this coronal mass ejection comes towards Earth but to be sure of that we need to have coronagraph imagery from SOHO, something that is not yet available at this time.

We also issue a warning for a possible minor solar radiation storm but it is still unlikely that the S1 threshold will be reached as sunspot region 2297 did not pass the central meridian yet.

Animation: The eruptive nature of the X2.2 solar flare can be seen nicely in these difference images from NASA SDO. Note the bulk of the ejecta looks to be heading to the east.

M-class solar flares

There were also a number of lesser M-class solar flares (M2.9 at 00:02 UTC, M1.8 at 07:18, M2.6 at 07:57 UTC, M1.0 at 18:51 UTC) today but coronagraph imagery is also very limited for these events. We can say for sure that the M2.9 solar flare from 00:02 UTC did launch a small coronal mass ejection but that was directed away from Earth. We need more imagery from SOHO for the other events.

NOAA SWPC alerts regarding the X2.2 solar flare

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2015 Mar 11 1617 UTC
NOAA Scale: R2 - Moderate

ALERT: Type II Radio Emission
Begin Time: 2015 Mar 11 1623 UTC
Estimated Velocity: 1461 km/s

ALERT: Type IV Radio Emission
Begin Time: 2015 Mar 11 1638 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2015 Mar 11 1611 UTC
Maximum Time: 2015 Mar 11 1622 UTC
End Time: 2015 Mar 11 1629 UTC
X-ray Class: X2.1
Optical Class: 2b
Location: S17E23
NOAA Scale: R3 - Strong

Sunspot region 2297

Sunspot region 2297 continued to grow during the day, increasing both in spot count and magnetic complexity. Several new delta spots emerged near the leading spot in the eastern part of the region but they are not yet very compact. In the cluster west of the leading spot a strong delta spot sits close to the spot of opposite polarity making it very complex. The potential for more solar flares from this sunspot region increased a lot during the day with M-class flares being very likely and a fair chance for another X-class event. Now that the sunspot region is almost near the center of the earth-facing solar disk, there is an increasing possibility that a proton event might occur and any coronal mass ejections will head towards Earth.

M-class flare probability for the coming 24 hours: 80% chance
X-class flare probability for the coming 24 hours: 30% chance

Image: Sunspot region 2297 as seen by NASA SDO. Delta sunspots are indicated by arrows.