Monday, October 01, 2012

AR 1583s M1 Flare on Sept 30th...

The above image was taken September 30th at 04:33:00 UTC by the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). This was during the time of a M1 solar ex-ray event, produced by Active Region 1583 (AR 1583), on the western (right) limb. The displayed image combined the AIA observations at 94, 131, and 171 Angstroms. Image Credit: SDO/AIA

For the end of September 29th and most of September 30th, the solar activity has been at moderate levels. Active Region 1583 (AR 1583) produced an isolated M1 solar x-ray event on the 30th at 04:33 UTC. AR 1583 had grown rapidly, however it is only hours away from rotating off the solar disk and out of view. The remaining active regions on the disk remained stable, producing a few low level C-class events. New AR 1584 was numbered, and as of this writing, had only produced one low level C-class event. No Earth directed coronal mass ejections (CMEs) were observed. The forecast through October 3rd: The solar activity is expected to be at low levels with a slight chance for continued M-class activity for the 1st and 2nd. A return to low levels is expected on the 3rd, as the active region cluster, located in the northwest quadrant, rotates around the west limb.

Here at home, the geomagnetic field has been at quiet to active levels. The enhanced activity was due to the arrival of a CME from the 27th. On the 30th at around 11:00 UTC, measurements, from the Advanced Composition Explorer (ACE) spacecraft, indicated the arrival of this CME. At 11:38 UTC, a sudden impluse of 15 nT was measured by the Boulder magnetometer, as the CME reached Earth. Solar wind velocities increased very little with this initial phase of the CME, increasing from around 280 - 320 km/s. The total interplanetary magnetic field (IMF) increased as the CME arrived, with sustained periods of negative Bz. However, with the lower than expected solar wind speeds, very little geomagnetic effects have been observed. The forecast through October 3rd: The geomagnetic field is expected to be a quiet to active levels with minor storm periods possible on the 1st, as effects of today's CME continue. Quiet to unsettled levels are expected on the 2nd as CME effects wane. A return to predominantly quiet levels is expected on the 3rd. Stay tuned...

To monitor solar flare activity minute by minute, visit the "Today's Space Weather" page of NOAA's Space Weather Prediction Center (

To learn more about the sun and to stay current on solar activity, visit the mission home pages of the Solar Dynamics Observatory (SDO) (, the Solar and Heliospheric Observatory (SOHO) (, the Advanced Composition Explorer (ACE) (, and the Solar Terrestrial Relations Observatory (STEREO) (


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