Last update issued on June 22, 2003 at 03:05 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update June 3, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update June 3, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 3, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update April 13, 2003)]
[Archived reports (last update June 17, 2003)]
The geomagnetic field was unsettled to minor storm on June 21. Solar wind speed ranged between 472 and 564 km/sec under the influence of a high speed stream from coronal hole CH45.
Solar flux measured at 20h UTC on 2.8 GHz was 115.0. The planetary A
index was 23 (STAR Ap - based on the mean of three hour interval ap indices: 23.8).
Three hour interval K indices: 44533433 (planetary), 23322532 (Boulder - source USAF).
The background x-ray flux is at the class B2 level.
At midnight there were 3 spotted regions on the visible disk. Solar flare activity was low. A total of 4 C class events was recorded during the day.
Region 10386 decayed slowly and appears to have lost its magnetic delta structure. A minor M class flare is possible. Flares:
C1.7 at 00:14 and C1.4 at 17:30 UTC.
Region 10387 increased its penumbral area further but remained fairly simply structured.
Region 10388 decayed slowly with most of the leading spots disappearing and the main penumbrae losing some area. Slow development was observed between the trailing and intermediate spot sections. Flares: C2.2 at 02:35 and C2.5 at 13:13 UTC.
June 19-21: 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 new coronal hole (CH45) in the southern hemisphere was in a geoeffective position on June 18-19. A huge, recurrent coronal hole (CH46) mainly in the southern hemisphere but with trans equatorial extensions will rotate into a geoeffective position on June 25-29. A new coronal hole in the northern hemisphere is developing but is probably too far to the north to become geoeffective.
Processed SOHO EIT 284 image at 01:06 UTC on June 22. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to active on June 22-23 as a high speed stream from coronal hole CH45 dominates the solar wind. Quiet to unsettled is likely on June 24-26.
Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor and will likely stay very poor until at least June 24. Propagation along north-south paths is poor to fair. [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 EAO
at midnight, area 0330
|Total spot count:||68||74|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2002.12||157.2||80.8||(81.4 predicted, -3.8)|
|2003.01||144.0||79.5||(78.3 predicted, -3.1)|
|2003.02||124.5||46.2||(73.3 predicted, -5.0)|
|2003.03||131.4||61.5||(67.6 predicted, -5.7)|
|2003.04||126.4||60.0||(62.7 predicted, -4.9)|
|2003.05||115.7||55.2||(57.8 predicted, -4.9)|
|2003.06||133.5 (1)||81.2 (2)||(53.8 predicted, -4.0)|
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 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.