Last update issued on June 29, 2003 at 02:55 UTC.
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[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 major storm on June 28. Solar wind speed ranged between 609 and 763 km/sec under the influence of a high speed stream from coronal hole CH46.
Solar flux measured at 20h UTC on 2.8 GHz was 123.9. The planetary A
index was 32 (STAR Ap - based on the mean of three hour interval ap indices: 33.1).
Three hour interval K indices: 35365444 (planetary), 35464434 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 9 spotted regions on the visible disk. Solar flare activity was low. A total of 3 C class events was recorded during the day.
decayed and lost all trailing spots, the region will soon rotate over the northwest limb.
Region 10390 was quiet and stable.
Region 10391 decayed further and lost all trailing spots. Flare: C1.0 at 14:49 UTC.
Region 10392 was quiet and stable.
Region 10393 decayed and had only a few small spots left by the end of the day.
Region 10394 developed early in the day, then the positive and negative polarity fields drifted apart and the region appears to have stopped developing. Flare: C4.3 at 06:56 UTC.
Region 10395 decayed slightly and was quiet..
Region 10396 developed slowly and was mostly quiet.
Region 10397 rotated fully into view revealing a magnetic delta structure in the easternmost trailing penumbra. M class flaring is possible. Flare: C3.0 at 15:40 UTC (there was a simultaneous event in region 10391, that event may have contributed to the flare intensity).
June 26-28: No LASCO images available. There is a serious problem with the SOHO high gain antenna. Current LASCO images and nearly all other SOHO data is expected to be unavailable until about July 14.
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 June 30. The trans equatorial extension has become much larger over the last solar rotation.
Processed GOES SXI coronal structure image at 20:04 UTC on June 28. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to major storm until July 1, unsettled to active is likely on July 2-4.
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. [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 HSX
at midnight, area 0090
classification was HAX
at midnight, area 0120
classification was AXX
at midnight, area 0010
classification was CSO
classification was DAI
classification was FKO
|Total spot count:||61||66|
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||129.4 (1)||109.4 (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.