Last update issued on February 9, 2003 at 05:45 UTC.
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[Solar cycles 21-23 (last update February 2, 2003)]
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The geomagnetic field was quiet to active on February 8. Solar wind speed ranged between 458 and 553 km/sec under the influence of a coronal stream.
Solar flux measured at 20h UTC on 2.8 GHz was 139.2. The planetary A
index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 13.6).
Three hour interval K indices: 32334333 (planetary), 32323323 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 11 spotted regions on the visible disk, 1 of which has not yet been numbered by SEC/NOAA. Solar flare activity was low. Only 1 C class event was recorded during the day.
Region 10274 was quiet and stable.
Region 10276 decayed slowly. This region has many spots but only two of them have penumbra.
Region 10277 decayed slowly and quietly.
Region 10278 was mostly unchanged and quiet.
Region 10279 reemerged with a few spots.
Region 10280 decayed slowly and quietly.
Region 10281 was quiet and stable.
Region 10283 developed slowly and may be capable of producing further C class flares. Flare: Long duration C1.4 peaking at 13:15 UTC.
New region 10284 emerged in the northwest quadrant.
New region 10285 rotated into view at the southeast limb.
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: S04W79.
February 6-7: No obviously geoeffective CMEs observed. (Images covering February 8 not yet available.)
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 coronal hole in the southern hemisphere is currently rotating into view. It remains to be seen if it has any possibly geoeffective extensions.
Processed SOHO EIT 284 image at 01:06 UTC on February 9. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on February 8-11. 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 AXX
split off from region
|Total spot count:||62||75|
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||137.0 (1)||29.2 (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.