Solar Terrestrial Activity Report

Last update November 13, 2002 at 04:15 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 2, 2002)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 2, 2002)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update November 2, 2002)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)]
[Archived reports (last update November 9, 2002)]

Recent activity

The geomagnetic field was quiet to active on November 12. Solar wind speed ranged between 482 and 690 km/sec, slowly decreasing all day. The combined disturbance caused by a coronal stream and the CME which arrived after noon on November 11, continued with stronger southward IMF excursions noted towards the end of the day.

Solar flare activity was moderate. Solar flux was 178.2, the planetary A index was 14 (STAR Ap - based on the mean of three hour ap indices: 14.4).
Three hour interval K indices: 22334334 (planetary), 13233233 (Boulder).

The background x-ray flux is at the class B8 level.

At midnight there were 8 spotted regions on the visible disk. A total of 11 C and 1 M class events were recorded during the day.

Region 10180 decayed slowly as it began to rotate out of view at the southwest limb. Further M class flares are possible over the next 1-2 days while the region is at and just behind the limb. Flares: C4.8 at 00:30, C2.1 at 00:57, C2.0 at 01:41, C2.7 long duration event peaking at 02:18, C1.5 at 05:28, C5.3 at 07:49, C9.9/2N at 18:18 and M2.9/1N at 18:56 UTC.
Region 10182 was quiet and stable.
Region 10185 decayed slowly in the leading penumbral area while slow growth was observed in the trailing spots.
Region 10189 reemerged with a few small spots.
Region 10190 was quiet and stable
Region 10191 developed in the leading spot section adding penumbral area and a few spots. M class flares are possible. Flare: C2.1 at 18:06 UTC.
Region 10192 decayed slowly and quietly and could soon become spotless.
New region 10193 emerged in the southeast quadrant.

Coronal mass ejections (CMEs)

November 11: A large filament eruption in the southern hemisphere began near 11h UTC and produced a partial halo CME. The CME is probably not geoeffective. A long duration M1 event in region 10180 after 16h UTC was associated with a CME off the southwest limb. A long duration C7 event in region 10191 was likely associated with a CME off of the southeast limb late in the day.

November 12: A CME was observed off of the southwest limb after the M2.9 flare in region 10180, the CME is not geoeffective.

Coronal holes

A trans equatorial coronal hole will be in a geoeffective position on November 12-13.

Enhanced SOHO EIT 284 image at 19:06 UTC on November 12. The black areas on the solar disk  are coronal holes.

Forecast

The geomagnetic field is expected to be quiet to active on November 13-15, isolated minor storm intervals are possible on November 14 and on November 15 after the arrival of a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor.

Coronal holes (1)	Coronal mass ejections (2)	M and X class flares (3)

1) Effects from a coronal hole could reach Earth within the next 5 days.
2) Material from a CME is likely to impact Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% probability.

Active solar regions (Recent map)

The above image is a test composite image displaying the currently spotted regions overlaid by a coronal hole image. The basis for the region image is a SOHO/MDI image late on November 11. Region numbering and other image processing has been applied by myself. 

Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is the STAR spot count (spots observed at or just prior to midnight) and data for regions not numbered by SEC or where SEC has observed no spots.

Monthly solar cycle data

1) Running average based on the daily 20:00 UT observed solar flux value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-45% less.

This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. Comments and suggestions are always welcome.