Report for January 19 issued on January 20, 2003 at 03:20 UTC.
[Solar and geomagnetic data
- last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update January 1, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)]
[Archived reports (last update January 13, 2003)]
The geomagnetic field was quiet to active on January 18. Solar wind speed ranged between 359 and 478 km/sec as a coronal stream began to dominate the solar wind. The source of this coronal stream is likely the northwesternmost extension of the southern polar coronal hole.
Solar flux measured at 20h UTC on 2.8 GHz was 137.4. The planetary A
index was 12 (STAR Ap - based on the mean of three hour interval ap indices: 13.1).
Three hour interval K indices: 22334322 (planetary), 22334323 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 9 spotted regions on the visible disk, 2 of which has not yet been numbered by SEC/NOAA. Solar flare activity was very low. No C class flares were recorded.
Region 10250 developed slowly as new spots emerged south of the largest penumbra.
Region 10251 decayed slowly and quietly.
Region 10254 decayed slowly and quietly with the trailing penumbra losing area.
Region 10255 was split off from region 10251 on January 12 by SEC/NOAA. This split was doubtful even then and it is
currently obvious that it was a premature decision.
Region 10256 was split off from region 10254 on January 12 by SEC/NOAA. Regions 10254 and 10256 make up one bipolar region with the negative polarity area in the west and the positive area to the east. It remains to be seen if SEC will merge the "two" regions again.
Region 10257 lost area in the main penumbra, however, a few small spots emerged.
Region 10258 was quiet and stable.
Region 10259 decayed slowly and quietly.
Region 10260 developed slightly and was quiet.
Spotted regions not numbered by SEC/NOAA:
[S75] A new region emerged in the southwest quadrant north of region 10254. Location at midnight: S06W32.
[S76] A new region emerged in the northwest quadrant. Location at midnight: N26W31.
January 16-18: No obviously geoeffective CMEs observed.
Coronal hole history (since late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
An extension of the southern polar coronal hole was in a geoeffective position on January 18, a northwestern extension may have been in a geoeffective position on January 16. A large trans equatorial coronal hole has split off from the southern polar coronal hole and will be in a geoeffective position on January 18-22.
Processed SOHO EIT 284 image at 19:06 UTC on January 18. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active until January 26 due to coronal streams, occasional minor storm intervals are possible. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair.
|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.
Composite image based on a SOHO/MDI continuum image and overlaid by a coronal hole image. Region numbering has been included. Compare to the previous day's image.
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 inside a few hours before midnight) and data for regions not numbered by SEC or where SEC has observed no spots.
|Solar region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
classification was HSX
at midnight, area 0080,
region 10255 included
classification was ESO
at midnight, area 0120.
STAR spot count
includes region 10256.
split off from region
split off from region
10254. Only positive
|Total spot count:||48||51|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2002.07||173.5||99.6||(102.1 predicted, -4.1)|
|2002.08||183.6||116.4||(98.5 predicted, -3.6)|
|2002.09||175.8||109.6||(95.5 predicted, -3.0)|
|2002.10||167.0||97.5||(92.0 predicted, -3.5)|
|2002.11||168.7||95.0||(86.7 predicted, -5.3)|
|2002.12||157.2||81.6||(82.4 predicted, -4.3)|
|2003.01||155.5 (1)||92.0 (2)||(79.4 predicted, -3.0)|
1) Running average based on the daily 20:00 UT observed solar flux value at 2800
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. All time references are to the UTC day. Comments and suggestions are always welcome.