Solar Terrestrial Activity Report

Last update November 24, 2002 at 02:30 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 minor storm on November 23. Solar wind speed ranged between 463 and 582 km/sec under the weakening influence of a coronal stream. 

Solar flare activity was low. Solar flux was 147.5, the planetary A index was 19 (STAR Ap - based on the mean of three hour ap indices: 19.6).
Three hour interval K indices: 45433332 (planetary), 36432211 (Boulder).

The background x-ray flux is at the class B5 level.

At midnight there were 7 spotted regions on the visible disk, 1 of which has not yet been numbered. A total of 9 C class events were recorded during the day.

Region 10195 gained a few trailing spots and was otherwise unchanged and quiet.
Region 10197 was quiet and stable.
Region 10198 developed slowly adding several trailing spots. M class flares are possible. Flares: C1.3 at 01:12, C1.9 at 08:42, C1.0 at 13:13,  C1.6 at 14:07, C3.4 at 15:42, C1.0 at 17:45 UTC.
Region 10199 decayed slowly and quietly.
Region 10200 was quiet and stable.
Region 10201 decayed slowly and quietly.

Spotted regions which have not yet been numbered:
[S35] A spotted region began to rotate into view at the northeast limb late in the day. This region has been quite active and could produce minor M class flares. Location at midnight N13E86.  Flares: C2.1 at 01:25, C4.6 at 08:04 and C2.7 at 18:10 UTC.

Coronal mass ejections (CMEs)

November 21-23: No obviously geoeffective CMEs noted. A full halo CME observed on Nov.20 appears to have had a backside origin.

Coronal holes

An extension of the southern polar coronal hole will rotate into a geoeffective position on Nov.23-24. A trans equatorial coronal hole is rotating into view at the east limb.

Processed SOHO EIT 284 image at 19:06 UTC on November 23. The black areas on the solar disk are coronal holes.

Forecast

The geomagnetic field is expected to be quiet to active on Nov.24 and quiet to unsettled on Nov.25 and most of Nov.26. Another coronal stream could reach Earth late on Nov.26 and cause unsettled to active conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very 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)

Composite image based on a SOHO/MDI continuum image and overlaid by a coronal hole image. Region numbering has been included.

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.