Last update issued on June 24, 2003 at 02:50 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 23, 2003)]
The geomagnetic field was unsettled to minor storm on June 23. Solar wind speed ranged between 453 and 583 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 113.5. The planetary A
index was 20 (STAR Ap - based on the mean of three hour interval ap indices: 21.0).
Three hour interval K indices: 45443333 (planetary), 35443333 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 6 spotted regions on the visible disk. Solar flare activity was very low with no events reaching the C class level.
Region 10386 decayed further and lost nearly all spots outside of the penumbra containing the magnetic delta structure.
Region 10387 decayed slowly and quietly.
Region 10388 decayed quickly and will become spotless later today if the current rate of decay persists.
Region 10390 lost its negative polarity spots and was quiet.
New region 10391 emerged in the northeast quadrant on June 22 and was numbered the next day by SEC.
Spotted regions not numbered by SEC:
[S192] A new region emerged late on June 23 in the northeast quadrant just ahead of the leading edge of coronal hole CH46. Location at midnight: N05E08.
June 21-23: 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 huge, recurrent coronal hole (CH46) mainly in the southern hemisphere and with a large leading trans equatorial extension will rotate into a geoeffective position from late on June 24 until July 2.
Processed SOHO EIT 284 image at 01:06 UTC on June 24. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to active on June 24 as a high speed stream from coronal hole CH45 dominates the solar wind. Quiet to unsettled is likely on June 25-26 and early on June 27. Then a high speed stream from coronal hole CH46 will cause unsettled to major storm conditions until July 1 becoming unsettled to active on July 2-4.
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 25. Propagation along north-south paths is 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
classification was ESO
at midnight, area 0030
|10391||2003.06.23||9||15||N15E03||0060||DAO||formerly region S191|
|Total spot count:||54||62|
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||131.6 (1)||87.8 (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.