Last update issued on October 9, 2003 at 04:05 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 quiet to unsettled on October 8. Solar wind speed ranged between 474 and 678 km/sec. A slow increase in wind speed was noted between 04 and 17h UTC and the high speed stream intensified towards the end of the day.
Solar flux measured at 20h UTC on 2.8 GHz was 113.3. The planetary A
index was 9 (STAR Ap - based on the mean of three hour interval ap indices: 10.3).
Three hour interval K indices: 22223333 (planetary), 31222223 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 5 spotted regions on the visible disk. Solar flare activity was low. Only 1 C class event was recorded during the day.
Region 10471 decayed slightly with the largest penumbrae losing area. Flare: C1.0
at 03:18 UTC.
Region 10473 was quiet and stable.
Region 10477 developed slowly and quietly.
Spotted regions not numbered by NOAA/SEC:
[S272] A new region emerged in the northeast quadrant early on October 8. The region has some polarity intermixing and could develop further. Location at midnight: N12E08.
[S273] This region emerged early on October 8 near the northeast limb. Location at midnight: N13E57.
October 6 and 8: 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
There is a small coronal hole in the northern hemisphere which will rotate across the central meridian on October 8. This coronal hole is likely too far to the north to become geoeffective. A recurrent trans equatorial coronal hole (CH62) will rotate to a geoeffective position on October 10.
Processed SOHO/EIT 284 image at 20:30 UTC on October 8. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on October 9 due to a high speed stream and quiet to unsettled 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 poor. Propagation along north-south paths is fair to poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay].
|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 HSX
classification was CAO
at midnight, area 0060
|Total spot count:||39||44|
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||118.5 (1)||23.6 (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.