Last update January 5, 2003 at 05:00 UTC.
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The geomagnetic field was quiet to active on January 4. Solar wind speed ranged between 473 and 654 km/sec under the influence of a coronal stream. Solar wind speed peaked before noon and decreased for the remainder of the day as the coronal stream subsided.
Solar flux measured at 20h UTC on 2.8 GHz was 143.0. The planetary A
index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 14.8).
Three hour interval K indices: 44223332 (planetary), 33223332 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 8 spotted regions on the visible disk, 3 of which have not yet been numbered. Solar flare activity was low. A total of 5 C class events were recorded during the day.
Region 10239 decayed further and had only a single tiny spot left at the end of the day.
Region 10241 decayed and was spotless by late evening.
Region 10242 developed further. A few small negative polarity areas emerged inside the trailing positive polarity area. There is currently no magnetic delta structure, however, a delta could form today if the current development continues. A minor M class flare is possible.
Region 10243 developed slowly and has only a minor chance of producing an M class flare. Flares: C1.0 at 08:13 and C1.4 at 11:32 UTC.
Region 10244 developed slowly. A minor M class flare is a remote possibility. Flares: C1.9 at 09:03 and C1.3 at 17:03 UTC.
Region 10245 developed slowly and quietly.
Spotted regions not yet numbered by SEC/NOAA:
[S66] A new region emerged northeast of region 10239. Location at midnight: S06W37. Unfortunately and confusingly SEC/NOAA decided to reuse region number 10240.
[S67] A new region emerged in the southeast quadrant to the east northeast of region 10244. Location at midnight: S15E55.
[S68] A new region emerged late in the day halfway between regions 10242 and 10245. Location at midnight: N02E45.
January 2-4: 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
A recurrent trans equatorial extension of the northern polar coronal hole will rotate into a geoeffective position on January 6-7.
Processed SOHO EIT 284 image at 19:06 UTC on January 4. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on January 5-8 becoming quiet to active on January 9-10 due to a coronal stream. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is 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 AXX
at midnight, area 0000
see region S66 below
area approx. 0250
area approx. 0220
|Total spot count:||47||85|
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||128.5 (1)||11.2 (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. Comments and suggestions are always welcome.