Last update issued on March 6, 2003 at 03:15 UTC.
[Solar and geomagnetic data
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[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 5. Solar wind speed ranged between 441 and 556 km/sec. The high speed stream from coronal hole CH23 was overlapped by a high speed stream from coronal hole CH24. This overlap occurred near noon.
Solar flux measured at 20h UTC on 2.8 GHz was 148.5. The planetary A
index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 16.5).
Three hour interval K indices: 32344333 (planetary), 32343433 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 6 spotted regions on the visible disk. Solar flare activity was very low.
Region 10295 decayed slowly and quietly.
Region 10296 decayed slowly in the leading spot section. Decay was observed in the trailing spot section as well with the two largest spots losing their penumbra. Some small trailing spots emerged.
Region 10297 added quite a few small spots both northwest and southeast of the main spots.
Region 10300 reemerged with a single spot.
Region 10301 did not change much and was quiet.
Region 10302 was quiet and stable.
March 4-5: No obviously geoeffective CMEs observed.
March 3: A CME was observed after a long duration C2.4 event in and near region S117 late in the day. While most of the ejected material was observed off of the southeast limb, the LASCO C3 movie indicates that there was a full halo CME. It is difficult to tell whether or not there was a nearly simultaneous backsided CME which contributed to the apparent halo CME or if the CME associated with the LDE was the only source. In the latter case the CME would likely impact Earth on March 6.
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 coronal hole (CH24) in the southern hemisphere was in a geoeffective position on March 2-3.
Processed SOHO EIT 284 image at 19:06 UTC on March 5. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active until March 7 due to a high speed stream from CH24. Quiet to unsettled conditions are likely from March 8. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor, propagation along north-south paths is fair to good. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. After Cristals s/off at 0200 Radio Rafaela (Argentina) and Radio Abril (Uruguay) as well as a couple of unidentified stations from Brazil were noted]
|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 CAO
classification was FKI
at midnight, STAR spot
count includes region
classification was CSO
only negative polarity
spots, these are the
trailing spots of region
classification was HRX
|Total spot count:||58||64|
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||143.0 (1)||18.1 (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.