Last update December 8, 2002 at 04:35 UTC.
[Solar and geomagnetic data
- last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update December 2, 2002)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2002)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 2002)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)]
[Archived reports (last update December 1, 2002)]
The geomagnetic field was unsettled to active on December 7. Solar wind speed ranged between 428 and 630 km/sec under the influence of a coronal stream.
Solar flare activity was low. Solar flux was 151.1, the planetary A
index was 16 (STAR Ap - based on the mean of three hour ap indices: 17.6).
Three hour interval K indices: 33343333 (planetary), 43333233 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight there were 11 spotted regions on the visible disk, 4 of which have not yet been numbered. A total of 2 C class flares were recorded during the day. A C2.1 event at 10:00 UTC could not be traced to any of the visible regions.
Region 10207 was quiet and stable.
Region 10208 decayed quickly and could become spotless today.
Region 10209 lost its trailing spots again while no changes were observed for the leading penumbra.
Region 10212 lost several of its smaller spots, the main penumbra was mostly unchanged.
Region 10213 decayed and lost more than half of its penumbral area. If the current rate of decay persists, the region will become spotless tomorrow.
Region 10214 developed further in the trailing spots section. C class flaring is likely and there is a chance of a minor M class flare. Flare: C1.0 at 18.51 UTC.
Region 10215 developed slowly. The single penumbra appears to be splitting into two.
Spotted regions not yet numbered by SEC:
[S43] A new region emerged in the southeast quadrant on December 6. The region decayed slowly on Dec.7 and had only a single small spot left by the end of the day. Location at midnight: S08E03.
[S44] A new region emerged in the southwest quadrant on December 7. Location at midnight: S24W24.
[S45] A new region emerged at the northeast limb. Location at midnight: N11E70.
[S46] A new region was rotating into view at the southeast limb late on December 7. Location at midnight: S20E80.
December 5-6: No obviously geoeffective CMEs noted.
Coronal hole history (starting late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 26 days ago 25 days ago
A slowly developing trans equatorial coronal hole was in a geoeffective position on December 4. A small, decaying, recurrent coronal hole in the southern hemisphere could rotate into a geoeffective position on December 10.
Processed SOHO EIT 284 image at 19:06 UTC on December 7. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on December 8 and quiet to unsettled on December 9-10. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair to 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.
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 just prior to 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|
area was near 0010 at
classification was HAX
|Total spot count:||36||47|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2002.06||148.7||88.3||(106.4 predicted, -2.4)|
|2002.07||173.5||99.9||(102.8 predicted, -3.6)|
|2002.08||183.6||116.4||(99.6 predicted, -3.2)|
|2002.09||175.8||109.3||(96.6 predicted, -3.0)|
|2002.10||167.0||97.5||(93.1 predicted, -3.5)|
|2002.11||168.7||95.0||(87.8 predicted, -5.3)|
|2002.12||148.3 (1)||29.1 (2)||(83.5 predicted, -4.3)|
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.
|[DX-Listeners' Club] [DX News]|