Last update issued on January 26, 2003 at 04:10 UTC.
[Solar and geomagnetic data
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[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 20, 2003)]
The geomagnetic field was quiet to minor storm on January 25. Solar wind speed ranged between 621 and 771 km/sec under the influence of a strong coronal stream.
Solar flux measured at 20h UTC on 2.8 GHz was 128.9. The planetary A
index was 28 (STAR Ap - based on the mean of three hour interval ap indices: 28.6).
Three hour interval K indices: 44554322 (planetary), 35554312 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 5 spotted regions on the visible disk, 1 of which has not yet been numbered by SEC/NOAA. Solar flare activity was low. A total of 4 C class events were recorded.
Region 10266 continued to lose trailing spot, however, slow development was observed in the leading spots.
Region 10267 decayed slowly and quietly. Flare: C1.2 at 05:13 UTC.
Region 10268 decayed as the trailing positive polarity spot split off from the leading spots. This is a reversed polarity region. Flares: C1.9 long duration event peaking at 08:36 and C4.4 at 18:55 UTC.
Region 10269 was quiet and stable.
Spotted regions not yet numbered by SEC:
[S80] A new region emerged in the southeast quadrant east of region 10269. Location at midnight: S07E38.
January 23 and 25: No obviously geoeffective CMEs observed.
January 24: A weak partial halo CME was observed in LASCO C2 images early in the day and appears to have been associated with the M1.9 event in region 10266 at 03:27 UTC. The CME could be geoeffective.
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
A small trans equatorial coronal hole will likely rotate into a geoeffective position on January 27. Another coronal hole in the northern hemisphere will probably become geoeffective on January 29-30.
Processed SOHO EIT 284 image at 01:06 UTC on January 26. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active until January 27 due to a coronal stream. Quiet to unsettled is expected on January 28-29 with quiet to active likely on January 30-31. 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.
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, only
negative polarity spots
|Total spot count:||53||40|
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||149.0 (1)||125.1 (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.