Last update issued on February 7, 2003 at 03:00 UTC.
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[Solar cycles 21-23 (last update February 2, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2003)]
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The geomagnetic field was quiet to active on February 6. Solar wind speed ranged between 452 and 553 km/sec under the influence of a coronal stream.
Solar flux measured at 20h UTC on 2.8 GHz was 150. The planetary A
index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 16.8).
Three hour interval K indices: 23334333 (planetary), 23334343 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight there were 10 spotted regions on the visible disk, 4 of which have not yet been numbered by SEC/NOAA. Solar flare activity was moderate. A total of 4 C and 2 M class events was recorded during the day.
Region 10274 was quiet and stable.
Region 10276 decayed slowly and quietly.
Region 10277 developed slowly. Flare: C3.4 at 02:12 and C1.3 at 12:48 UTC.
Region 10278 decayed after the M flares early in the day. The region may be capable of generating an additional minor M class flare. Flares: M1.0 (impulsive) at 03:33, M1.2/1N at 03:49, C1.5 at 10:08 and C1.1 at 11:25 UTC.
New region 10280 emerged in the southeast quadrant on February 5 and was numbered the next day. The region developed early in the day, then decayed slightly.
New region 10281 rotated into view at the southeast limb late on February 5 and was numbered the next day.
Spotted regions not yet numbered by SEC/NOAA:
[S87] A new region emerged north of region 10274 on January 31. Initially it was not clear if this was a separate region and the spots were associated with region 10274. The region developed quickly on February 2 and it became obvious that regions 10274 and S87 were separate bipolar regions. Slow decay has been observed since February 4. Location at midnight: S04W52.
[S90] A new region emerged in the southeast quadrant on February 4. Location at midnight: S14E41.
[S96] A new region emerged near the center of the visible disk on February 6. Location at midnight: S03W08.
[S97] A new region emerged near the northeast limb on February 6. Location at midnight: N01E64
February 4-6: 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
No obvious coronal holes are currently approaching geoeffective positions.
Processed SOHO EIT 284 image at 01:06 UTC on February 7. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on February 7 due to a coronal stream and quiet to unsettled on February 8-10. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor, propagation along north-south paths 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.
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
SEC spot count
includes that of region
classification was CSO
SEC spot count
includes region S90
|10280||2003.02.06||5||7||S08E29||0040||DSO||formerly region S91|
|10281||2003.02.06||1||1||S14E73||0030||HSX||formerly region S94|
split off from region
|Total spot count:||65||62|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2002.08||183.6||116.4||(99.7 predicted, -3.0)|
|2002.09||175.8||109.6||(96.7 predicted, -3.0)|
|2002.10||167.0||97.5||(93.2 predicted, -3.5)|
|2002.11||168.7||95.0||(88.0 predicted, -5.2)|
|2002.12||157.2||81.6||(83.6 predicted, -4.4)|
|2003.01||144.0||79.5||(80.6 predicted, -3.0)|
|2003.02||135.0 (1)||18.1 (2)||(75.5 predicted, -5.1)|
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.