Last major update issued on June 28, 2004 at 04:20 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update June 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update June 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 2, 2004)]
[Historical solar and geomagnetic data charts 1954-2004 (last update April 28, 2004)]
[Archived reports (last update June 21, 2004)]
The geomagnetic field was quiet on June 27. Solar wind speed ranged between 308 and 350 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 97.2. The planetary A
index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 6.4).
Three hour interval K indices: 21122222 (planetary), 21122212 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 3 spotted regions on the visible disk. The solar flare activity level was low. A total of 5 C class events was recorded during the day. A C1.3 flare at 04:24 UTC had its origin at or behind the southeast limb.
Region 10635 rotated out of view at the southwest limb. Flares: C1.0 at 03:58, C2.3 at
15:57, C2.5 at 20:21 and C3.6 at 22:51 UTC.
Region 10637 was quiet and stable.
New region 10639 rotated into view at the northeast limb. Flare: C1.6 at 19:31 UTC.
New region 10640 rotated into view at the southeast limb.
June 25-27: Very few LASCO images available.
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 recurrent trans equatorial coronal hole (CH103) was in a geoeffective position on June 26-27.
Processed SOHO/EIT 284 image at 13:05 UTC on June 15. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on June 28-30 due to a high speed stream from coronal hole CH103.
|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. When the high speed stream has arrived
the color changes to green.
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.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is fair to good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Vibración (Venezuela). After local sunrise propagation stations from Argentina seemed to be favored with the Buenos Aires stations on 590, 790, 870 and 950 kHz heard well. Earlier several Brazilian stations had fair signals on frequencies above 1350 kHz. 1510 WWZN Boston had the best signal from North America, only a few stations from Newfoundland and Nova Scotia were heard otherwise.
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. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.
|Active region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
|10635||2004.06.14||3||S10W90||0210||CAO||rotated out of view|
classification was CRO
classification was DSO
|Total spot count:||18||19|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.12||114.9||46.5||(54.4 predicted, -2.3)|
|2004.01||114.1||37.2||(50.5 predicted, -3.9)|
|2004.02||107.0||46.0||(46.2 predicted, -4.3)|
|2004.03||112.0||48.9||(43.5 predicted, -2.7)|
|2004.04||101.2||39.3||(41.4 predicted, -2.1)|
|2004.05||99.8||41.5||(38.2 predicted, -3.2)|
|2004.06||98.7 (1)||72.4 (2)||(35.3 predicted, -2.9)|
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 analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.