Last update issued on March 8, 2003 at 04:15 UTC.
[Solar and geomagnetic data
- last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 3, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 3, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 3, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update January 27, 2003)]
[Archived reports (last update March 3, 2003)]
The geomagnetic field was quiet to active on March 7. Solar wind speed ranged between 420 and 552 km/sec under the influence of a high speed stream from coronal hole CH24 most of the day. This stream appeared to be ending late in the day.
Solar flux measured at 20h UTC on 2.8 GHz was 149.9. The planetary A
index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 13.9).
Three hour interval K indices: 33342233 (planetary), 34332232 (Boulder).
The background x-ray flux is at the class B3-B4 level.
At midnight there were 10 spotted regions on the visible disk, 2 of which have not yet been numbered by SEC/NOAA. Solar flare activity was very low.
Region 10295 decayed slowly and quietly and could become spotless today.
Region 10296 decayed slowly and quietly.
Region 10297 decayed slowly and was quiet.
Region 10301 developed slowly in the leader spots while slow decay was observed in the trailing spots.
Region 10302 was quiet and stable.
New region 10303 emerged in the southwest quadrant. The region was decaying late in the day and could soon become spotless.
[New region 10304 was numbered by SEC/NOAA. Unfortunately the spots in this region are the same as those in region 10297. The region should be deleted.]
New region 10305 emerged in the southeast quadrant and has developed moderately quickly. C class flares are possible.
New region 10306 rotated into view at the northeast limb. The region consists of a single, large penumbra.
Spotted regions not yet numbered by SEC/NOAA:
[S120] A new region emerged on March 7 in the southeast quadrant west of region 10305. Location at midnight: S23E10.
[S121] A new region emerged on March 7 in the southern hemisphere near the central meridian. Location at midnight: S20W02.
March 5-7: No obviously 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 coronal hole (CH25) is rotating into view at the southeast limb and will likely move into a geoeffective position on March 13.
Processed SOHO EIT 284 image at 01:06 UTC on March 8. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on March 8-12. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor, propagation along north-south paths is fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay, the Radio Rafaela (Argentina) and CPN Radio (Peru) after 02h UTC. On other frequencies North American stations began to appear after 04h UTC.]
|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 SEC/NOAA. 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 EKO
at midnight, STAR spot
count includes region
classification was CSO
at midnight, only
negative polarity spots
only negative polarity
spots, these are the
trailing spots of region
classification was HSX
classification was AXX
the spots are those
of region 10297,
this region should be
classification was DAO
at midnight, area 0060
|Total spot count:||81||62|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2002.09||175.8||109.6||(94.7 predicted, -4.0)|
|2002.10||167.0||97.5||(91.2 predicted, -3.5)|
|2002.11||168.7||95.0||(86.0 predicted, -5.2)|
|2002.12||157.2||81.6||(81.6 predicted, -4.4)|
|2003.01||144.0||79.5||(78.6 predicted, -3.0)|
|2003.02||124.5||46.2||(73.6 predicted, -5.0)|
|2003.03||145.0 (1)||28.5 (2)||(67.9 predicted, -5.7)|
1) Running average based on the daily 20:00 UT observed solar flux value at 2800
2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-45% less.
This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.