Last update issued on October 14, 2003 at 02:40 UTC. Minor update posted at 15:57 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 quiet to active on October 13. Solar wind speed ranged between 316 and 537 km/sec, increasingly under the influence of a high speed stream from coronal hole CH62.
Solar flux measured at 20h UTC on 2.8 GHz was 94.4. The planetary A
index was 13 (STAR Ap - based on the mean of three hour interval ap indices: 14.5).
Three hour interval K indices: 33233334 (planetary), 32234434 (Boulder).
The background x-ray flux is at the class B1-B2 level.
At midnight there was 1 spotted region on the visible disk. Solar flare activity was very low.
Region 10477 decayed slowly and quietly. This region could become spotless today. Unless new regions emerge that would leave the sun spotless for the first time since the last solar minimum.
Comment added at 15:57 UTC on October 14: The visible solar disk has been spotless since about 09h UTC today.
A high speed stream from coronal hole CH63 arrived sometime between 06 and 09h UTC today and caused a significant increase in the current geomagnetic disturbance with major storm levels recorded since then.
October 11-13: No potentially 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 hole (CH63) will rotate into a geoeffective position on October 12-17. CH63 has become much smaller over the last rotation.
Processed SOHO/EIT 284 image at 19:06 UTC on October 13. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to active on October 14 due to a high speed stream from coronal hole CH62. A high speed stream from coronal hole CH63 will likely cause unsettled to major storm conditions on October 15-17 and unsettled to active on October 18-20.
Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along north-south paths is poor to fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). With a new EWE antenna directed towards the northwest several North American stations were still audible today, one of them was CBT Grand Falls NL on 540 kHz].
|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
|Location at midnight||Area||Classification||Comment|
classification was HRX
|Total spot count:||5||2|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|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||112.9 (1)||32.8 (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.