Last update issued on June 30, 2003 at 03:05 UTC.
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[Solar cycles 21-23 (last update June 3, 2003)]
[Solar cycles 1-20]
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The geomagnetic field was unsettled to minor storm on June 29. Solar wind speed ranged between 655 and 779 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 127.3. The planetary A
index was 26 (STAR Ap - based on the mean of three hour interval ap indices: 26.9).
Three hour interval K indices: 43554344 (planetary), 43543434 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 7 spotted regions on the visible disk. Solar flare activity was low. A total of 4 C class events was recorded during the day. Region 10387 at the northwest limb produced a C3.9 flare at 11:01 UTC.
Region 10390 decayed slowly and quietly.
Region 10391 decayed slowly and will soon rotate over the northwest limb.
Region 10392 decayed slowly and could become spotless today.
Region 10394 decayed, particularly in the trailing spot section.
Region 10395 decayed slowly and quietly.
Region 10396 developed in the leader spots while some decay was observed in the intermediate and trailing spot sections. During the latter half of the day a positive polarity field emerged to the north of and near the intermediate negative polarity field. This appears to have caused the region to become more active and a minor M class flare is possible. Flares: C2.2 at 19:13 and C2.6 at 22:02 UTC. This region was the source of a C7.1 flare at 00:09 and a C8.6 flare at 02:24 UTC early on June 30.
Region 10397 developed in the northern part of the trailing spots section and a new magnetic delta appears to have formed in a quickly developing penumbra. M class flaring is possible. Flare: C1.2 at 02:47 UTC. The region generated a C4.4 flare at 00:18 and a C1.3 flare at 01:58 UTC early on June 30.
June 27-29: No LASCO images available. There is a serious problem with the SOHO high gain antenna. New 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 July 2. The trans equatorial extension has become much larger over the last solar rotation.
Processed GOES SXI coronal structure image at 19:40 UTC on June 29. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm until July 2, unsettled to active is likely on July 3-5.
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 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|
rotated out of view
late in the day
classification was CAO
classification was HSX
at midnight, area 0010
classification was FKO
|Total spot count:||42||45|
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||128.9 (1)||113.1 (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.