Last update issued on August 31, 2003 at 04:10 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update August 18, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update August 18, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update August 18, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update July 23, 2003)]
[Archived reports (last update August 28, 2003)]
The geomagnetic field was quiet to minor storm on August 30. Solar wind speed ranged between 485 and 641 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 114.0. The planetary A
index was 17 (STAR Ap - based on the mean of three hour interval ap indices: 17.6).
Three hour interval K indices: 45333332 (planetary), 45333432 (Boulder).
The background x-ray flux is at the class B2-B3 level.
At midnight there were 7 spotted regions on the visible disk. Solar flare activity was low. A total of 2 C class events was recorded during the day.
Region 10442 added a few spots during the first half of the day, however, these spots were gone by midnight. Flare:
C1.4 long duration event peaking at 05:14 UTC.
Region 10444 lost nearly all penumbral area while a few small spots emerged.
Region 10445 decayed and will likely become spotless today. Flare: C1.2 at 18:02 UTC.
Region 10447 decayed slowly and could become spotless today.
Region 10448 did not change significantly and remained quiet.
Region 10449 was quiet and unchanged.
Region 10450 was quiet and stable. Magnetograms suggest that regions 10449 and 10450 are one region with region 10449 containing the leading negative spots and region 10450 having the positive trailing spots.
August 28-30: 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 large recurrent coronal hole (CH54) in the northern hemisphere and with a trans equatorial extension, will rotate into a geoeffective position on August 29- September 2.
Processed GOES SXI coronal structure image at 00:00 UTC on August 31. Base SXI image courtesy of NOAA/SEC. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active until the first half of September 1. On September 1-5 a high speed stream from coronal hole CH54 will likely cause unsettled to minor storm conditions.
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 stations tonight: Radio Vibración (Venezuela). Several other frequencies had stations from Venezuela as well].
|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 BXO
at midnight, area 0010
classification was AXX
classification was DAO
probably the trailing
spots of region 10449
|Total spot count:||30||46|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.02||124.5||46.0||(77.2 predicted, -3.8)|
|2003.03||131.4||61.1||(71.5 predicted, -5.7)|
|2003.04||126.4||60.0||(66.6 predicted, -4.9)|
|2003.05||115.7||55.2||(61.7 predicted, -4.9)|
|2003.06||129.3||77.4||(57.7 predicted, -4.0)|
|2003.07||127.7||85.0||(54.1 predicted, -3.6)|
|2003.08||122.5 (1)||111.0 (2)||(52.3 predicted, -1.8)|
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.