Last update issued on June 9, 2003 at 02:20 UTC.
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The geomagnetic field was unsettled to minor storm on June 8. Solar wind speed ranged between 609 and 767 km/sec under the influence of a high speed stream from coronal hole CH42.
Solar flux measured at 20h UTC on 2.8 GHz was 153.4. The planetary A
index was 27 (STAR Ap - based on the mean of three hour interval ap indices: 28.4).
Three hour interval K indices: 45433444 (planetary), 44333444 (Boulder).
The background x-ray flux is at the class B8 level.
At midnight there were 7 spotted regions on the visible disk. Solar flare activity was moderate. A total of 14 C and 1 M class events was recorded during the day.
Region 10373 was quiet and stable and will rotate over the northwest limb today.
Region 10375 developed quickly in the trailing spot section while some decay was observed in the leading spots. further. The trailing spots contain a strong magnetic delta. The region has major flare potential with an increasing chance of an X class event occurring over the next couple of days. Flares: C3.6 at 03:59, C3.9/1F at 04:35, C5.7 at 05:06, C2.3 at 06:58, C1.6 at 07:21, C2.2 at 07:45, C1.3 at 10:10, C1.7 at 14:00 and C1.3 at 23:38 UTC
Region 10377 developed slowly and quietly.
Region 10378 decayed and lost all trailing spots.
Region 10380 developed slowly and has a strong magnetic delta structure within the large penumbra. Further M class flaring is likely and there is even a possibility of an X flare. Flares: C1.5 at 00:07, C1.8 at 01:14, C3.5 at 06:13, C7.5 at 11:46, C6.0 at 12:07, M4.0/2N at 16:11 UTC.
Spotted regions not yet numbered or misnumbered by NOAA/SEC:
[S178] A new region emerged in the southwest quadrant on June 6, developed slowly on June 7 before decaying on June 8. Please note that SEC has made a major mistake in reassigning region number 10376 to this region. The spotless region 10376 was located at S11W70 at midnight. Location at midnight: S14W57.
[S181] A new region emerged to the north of region 10377 in the northeast quadrant on June 8. Location at midnight: N15E12.
June 6-8: 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 (CH42) in the southern hemisphere was in a geoeffective position on May 29-June 6. A small coronal hole (CH43) in the northern hemisphere will rotate into a geoeffective position on June 12.
Processed SOHO EIT 284 image at 19:06 UTC on June 8. Any black areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on June 9 and quiet to active on June 10-11 due to a high speed stream from coronal hole CH42.
Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor and will likely stay poor to very poor until at least June 12. 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 with a rather a weak signal.]
|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|
region is spotless,
SECs spots belong
to region S178
classification was HSX
classification was DKC
|Total spot count:||107||168|
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||122.5 (1)||24.6 (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.