Last major update issued on December 7, 2003 at 05:20 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update December 2, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update December
2, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update December 1, 2003)]
The geomagnetic field was unsettled to active on December 6. Solar wind speed ranged between 358 and 530 km/sec under the influence of a high speed stream.
Solar flux measured at 20h UTC on 2.8 GHz was 108.9. The planetary A
index was 22 (STAR Ap - based on the mean of three hour interval ap indices: 22.0).
Three hour interval K indices: 44443443 (planetary), 53433344 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 3 spotted regions on the visible disk. Solar flare activity was moderate. A total of 10 C and 2 M class events were recorded during the day, nearly all of them occurring at and just behind the southwest limb in region 10510.
Region 10510 rotated out of view at the southwest limb. Flares: C1.1 at 07:47, C2.5 at
08:24, C4.1 at 10:02, M1.3 at 11:20, C1.0 at 14:22, M2.0 at 15:46, C1.0 at 17:30, C1.2 at 17:57, C1.4 at 18:11 and C4.1 at 19:39
UTC.
Region 10513 decayed slowly and quietly.
Region 10516 decayed slowly and quietly. Flares: C2.2 long duration event peaking
at 00:27 (associated with an erupting filament) and C1.5 at 16:38 UTC.
Region 10517 decayed significantly and was quiet.
Region 10518 reemerged with a single spot, then decayed again and was spotless at midnight.
December 6: Only a few LASCO images from early in the day are available as I write this. A CME can be observed off of the southwest limb and may be associated with the southwest quadrant erupting filament seen in EIT images. This CME may be partly earth directed.
December 4-5: No partly or fully earth directed 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 huge recurrent trans equatorial coronal hole (CH71) will be in a geoeffective position on December 4-12.
Processed SOHO/EIT 284 image at 13:06 UTC on December 6. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to minor storm on December 7 and unsettled to minor storm with occasional major and severe storm intervals on December 8-15 due to a high speed stream from coronal hole CH71.
Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor to useless. Propagation along long distance north-south paths is fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Rafaela (Argentina)].
| 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. When the high speed stream has arrived
the color changes to green.
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 NOAA/SEC. 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. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.
| Active region | Date numbered | SEC spot count |
STAR spot count |
Location at midnight | Area | Classification | Comment |
|---|---|---|---|---|---|---|---|
| 10510 | 2003.11.24 | 5 | S23W96 | 0010 | BXO | rotated out of view | |
| 10513 | 2003.11.26 | 1 | 1 | N11W62 | 0060 | HSX |
area was 0040 at midnight |
| 10515 | 2003.11.28 | S03W42 | plage | ||||
| 10516 | 2003.11.28 | 11 | 10 | S17W37 | 0100 | DAO |
classification was DSO at midnight, area 0060 |
| 10517 | 2003.11.30 | 19 | 11 | S07W06 | 0220 | DSO |
area was 0150 at midnight |
| 10518 | 2003.12.03 | S21W29 | plage | ||||
| 10519 | 2003.12.04 | 1 | S05W45 | 0010 | AXX | spotless | |
| S320 | emerged on 2003.12.05 |
S08W26 | plage | ||||
| Total spot count: | 37 | 22 | |||||
| SSN: | 87 | 52 | |||||
| Month | Average solar flux at Earth |
International sunspot number | Smoothed sunspot number |
|---|---|---|---|
| 2000.04 | 184.2 | 125.5 | 120.8 cycle 23 sunspot max. |
| 2000.07 | 202.3 | 170.1 | 119.8 |
| 2001.12 | 235.1 | 132.2 | 114.6 (-0.9) |
| 2002.11 | 168.7 | 95.5 | 85.2 (-5.3) |
| 2002.12 | 157.2 | 80.8 | 82.0 (-3.2) |
| 2003.01 | 144.0 | 79.7 | 80.9 (-1.1) |
| 2003.02 | 124.5 | 46.0 | 78.5 (-2.4) |
| 2003.03 | 131.4 | 61.1 | 74.1 (-4.4) |
| 2003.04 | 126.4 | 60.0 | 70.3 (-3.8) |
| 2003.05 | 115.7 | 55.2 | 67.8 (-2.5) |
| 2003.06 | 129.3 | 77.4 | (65.3 predicted, -2.5) |
| 2003.07 | 127.7 | 85.0 | (61.9 predicted, -3.4) |
| 2003.08 | 122.1 | 72.7 | (59.0 predicted, -2.9) |
| 2003.09 | 112.2 | 48.8 | (57.0 predicted, -2.0) |
| 2003.10 | 151.7 | 65.6 | (54.3 predicted, -2.7) |
| 2003.11 | 140.8 | 67.2 | (51.6 predicted, -2.7) |
| 2003.12 | 123.8 (1) | 21.5 (2) | (49.0 predicted, -2.6) |
1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC) sunspot number. The official international sunspot number is typically
30-50% less.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.
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