Last update issued on October 10, 2003 at 03:05 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update October 4, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 4, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October
4, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update July 23, 2003)]
[Archived reports (last update October 7, 2003)]
The geomagnetic field was mostly quiet on October 8 with the exception of a single active interval early in the day. Solar wind speed ranged between 456 and 651 km/sec under the influence of a high speed stream. This influence weakened through the day and appeared to be ending at 20h UTC at ACE.
Solar flux measured at 20h UTC on 2.8 GHz was 110.9. The planetary A
index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 9.9).
Three hour interval K indices: 42222222 (planetary), 422222231 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 6 spotted regions on the visible disk. Solar flare activity was low. Only 1 C class event was recorded during the day.
Region 10471 decayed quickly during the latter half of the day losing penumbral area and quite a few spots. The
region has simplified and no longer has mixed polarities. Flare: C2.9 at 23:46 UTC.
Region 10473 decayed slowly and quietly.
Region 10477 was mostly unchanged and quiet.
New region 10478 emerged early on October 8 in the northeast quadrant and was numbered the next day by SEC. The region
decayed fairly quickly on October 9 and could soon become spotless.
Spotted regions not numbered by NOAA/SEC:
[S274] A new region emerged in the northeast quadrant on October 9. Location at midnight: N10E13.
[S275] This small region rotated into view at the northeast limb on October 9. Location at midnight: N23E74.
October 8-9: No potentially geoeffective CMEs observed. No LASCO images available for October 7 and the first half of October 8.
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 coronal hole (CH62) will rotate to a geoeffective position on October 10. Another recurrent trans equatorial hole (CH63) will rotate into a geoeffective position on October 13-14.
Processed SOHO/EIT 284 image at 01:06 UTC on October 10. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on October 10-12. Quiet to active is likely on October 13-14 due to a high speed stream from coronal hole CH62.
Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair. Propagation along north-south paths is fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela) and Cadena Peruana de Noticias. Quite a few stations from the easternmost part of North America was heard on other frequencies].
| 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 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.
| Solar region | Date numbered | SEC spot count |
STAR spot count |
Location at midnight | Area | Classification | Comment |
|---|---|---|---|---|---|---|---|
| 10471 | 2003.09.30 | 19 | 21 | S08W44 | 0140 | DAI | |
| 10473 | 2003.10.03 | 1 | 2 | S08W62 | 0080 | HHX |
classification was HSX at midnight. HHX classification is not possible with area less than 0250. |
| 10475 | 2003.10.05 | S22W05 | plage | ||||
| 10476 | 2003.10.06 | S16W28 | plage | ||||
| 10477 | 2003.10.06 | 5 | 3 | S15E32 | 0050 | CHO |
classification was CSO at midnight CHO classification is not possible with area less than 0250. |
| 10478 | 2003.10.09 | 3 | 2 | N10W06 | 0010 | BXO |
formerly region S272 classification was HAX at midnight, CSO early in the day - not BXO |
| S267 | emerged on 2003.09.29 |
S18W89 | plage | ||||
| S269 | emerged on 2003.10.02 |
N10W88 | plage | ||||
| S273 | emerged on 2003.10.08 |
N13E44 | plage | ||||
| S274 | emerged on 2003.10.09 |
4 | N10E13 | 0010 | AXX | ||
| S275 | visible on 2003.10.09 |
2 | N23E74 | 0020 | CSO | ||
| Total spot count: | 28 | 34 | |||||
| SSN: | 68 | 94 | |||||
| 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) |
| 2002.09 | 175.8 | 109.6 | 94.6 (-4.1) |
| 2002.10 | 167.0 | 97.5 | 90.5 (-4.1) |
| 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 | (69.6 predicted, -4.5) |
| 2003.05 | 115.7 | 55.2 | (65.3 predicted, -4.3) |
| 2003.06 | 129.3 | 77.4 | (61.5 predicted, -3.8) |
| 2003.07 | 127.7 | 85.0 | (58.0 predicted, -3.5) |
| 2003.08 | 122.1 | 72.7 | (55.0 predicted, -3.0) |
| 2003.09 | 112.2 | 48.8 | (53.0 predicted, -2.0) |
| 2003.10 | 117.6 (1) | 25.8 (2) | (50.3 predicted, -2.7) |
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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