Last major update issued on March 10, 2004 at 04:45 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update March 2, 2004)]
[Historical solar and geomagnetic data charts 1954-2003 (last update January 16, 2004)]
[Archived reports (last update March 3, 2004)]
The geomagnetic field was quiet to minor storm on March 9. Solar wind speed ranged between 343 and 716 km/sec. A high speed stream from coronal hole CH84 increasingly influenced the geomagnetic field during the day.
Solar flux measured at 20h UTC on 2.8 GHz was 108.7. The planetary A
index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 22.0).
Three hour interval K indices: 12334445 (planetary), 12233545 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 4 spotted regions on the visible disk. Solar flare activity was low. A total of 2 C class events was recorded during the day.
Region 10569 decayed slowly and quietly.
Region 10570 decayed slowly and currently has no polarity intermixing. Flares: C1.1 at 04:35 and C1.3 at 06:48 UTC.
Spotted regions not numbered by NOAA/SEC:
[S368] This region emerged on March 8 in the southwest quadrant. Location at midnight: S04W77.
[S369] A new region emerged on a coronal island inside coronal hole CH84 on March 8. The region became spotless on March 9 before slowly reemerging late that day. Location at midnight: S14E00.
March 7-9: 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 large recurrent trans equatorial coronal hole (CH84) will be in a geoeffective position on March 7-11.
Processed SOHO/EIT 284 image at 01:06 UTC on March 10. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to major storm on March 10-14 due to a high speed stream from coronal hole CH84.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela) and Radio Cristal del Uruguay, both with fairly poor signals].
|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
|Location at midnight||Area||Classification||Comment|
|Total spot count:||20||32|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.09||112.2||48.7||(58.9 predicted, -1.1)|
|2003.10||151.7||65.5||(56.2 predicted, -2.7)|
|2003.11||140.8||67.3||(53.5 predicted, -2.7)|
|2003.12||114.9||46.5||(50.9 predicted, -2.6)|
|2004.01||114.1||37.2||(46.7 predicted, -4.2)|
|2004.02||107.0||46.0||(42.1 predicted, -4.6)|
|2004.03||102.5 (1)||15.3 (2)||(39.7 predicted, -2.4)|
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 some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.