Last major update issued on June 23, 2004 at 04:00 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 22. Solar wind speed ranged between 310 and 348 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 116.7. The planetary A
index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 4.8).
Three hour interval K indices: 11012221 (planetary), 11011021 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 4 spotted regions on the visible disk. The solar flare activity level was low. A total of 1 C class event was recorded during the day.
Region 10634 decayed further and has only a single large penumbra left.
Region 10635 decayed slightly in the leading spot section while some developed was observed to the west and northwest of the main trailing penumbra. There is still a chance of an M class flare. Flare: C1.7 at 22:11 UTC.
Spotted regions not numbered by NOAA/SEC:
[S420] This region was split off from region 10635 on June 19 as magnetograms suggested that this is a bipolar region by itself. The region has many small spots. The region decayed slightly on June 20 and then developed slowly on June 21 and 22. Location at midnight: S15W21.
[S423] A new region emerged in the southwest quadrant on June 22. Location at midnight: S14W47.
June 20-22: No LASCO images available after early on June 20. Other image sources do not indicate any significant activity during the interval.
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) will rotate into 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 mostly quiet on June 22-24.
|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 good. Trans Atlantic propagation conditions are monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Vibración (Venezuela). Weak audio was noted as early as 20:58 UTC and I can still hear these two stations as I write this well over one hour after local sunrise. On other frequencies stations from Uruguay (1440, 1480 and 1510 kHz) and Argentina (1430, 1500, 1610, 1620, 1630 kHz) were better compared to a day ago. 1510 WWZN Boston had a fair to good signal, only a few other and weak signals were observed from North America.
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|
|10632||2004.06.10||1||S12W91||0030||HAX||rotated out of view|
classification was HAX
location was N12W51
classification was FAI
location was S10W29
|S420||2004.06.19||18||S15W20||0040||DRI||split off from 10635|
|Total spot count:||63||72|
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||97.6 (1)||59.3 (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.