Last major update issued on June 29, 2006 at 03:55 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update June 7, 2006)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update June 7, 2006)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update June 7, 2006)]
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[Archived reports (last update June 5, 2006)]
The geomagnetic field was quiet to active on June 28. Solar wind speed ranged between 348 and 641 km/s (all day average 505 km/s - increasing 204 km/s over the previous day) under the influence of a high speed stream from CH229.
Solar flux measured at 20h UTC on 2.8 GHz was 83.5. The planetary A index
was 18 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 32444233 (planetary), 23534243 (Boulder).
The background x-ray flux is at the class A8 level.
At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10897 decayed slowly and quietly.
New region 10898 rotated into view at the southeast limb on June 27 and was numbered the next day by NOAA/SEC. C flares are possible. Polarity separation is poor.
Spotted regions not numbered by NOAA/SEC:
[S666] I split off this region from 10897 as this is a bipolar and slowly developing area. Location at midnight: N05E24
June 26-28: No partly or fully Earth directed CMEs were detected in LASCO imagery.
Coronal hole history (since late October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago
A recurrent trans equatorial coronal hole (CH229) was in an Earth facing position June 24-26. A recurrent coronal hole (CH230) in the northern hemisphere will likely rotate into an Earth facing location on July 2-3.
Processed SOHO/EIT 284 image at 01:06 UTC on June 29. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on June 29 and quiet on June 30 - July 2.
|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) Effects from a CME are likely to be observed at 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 very poor. Propagation on long distance northeast-southwest paths is fair to good. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Radio Cristal del Uruguay and Rafaela Argentina were both present tonight. On other frequencies propagation was best to Argentina (710, 950, 1030 and 1190 kHz had strong signals), Uruguay (excellent signal from 930 Radio Montecarlo and 1410 AM Libre) and southeast Brazil.
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|
|10897||2006.06.25||17||10||N05E29||0110||DRC||classification was CSI at midnight, area 0050
|10898||2006.06.28||1||5||S06E66||0150||HSX||formerly region S665
classification was DAO at midnight
|S666||2006.06.28||5||N05E24||0040||DSO||split off from 10897|
|Total spot count:||18||20|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2005.12||90.7||41.2||(22.8 predicted, -2.1)|
|2006.01||83.4||15.4||(20.1 predicted, -2.7)|
|2006.02||76.5||4.7||(17.1 predicted, -3.0)|
|2006.03||75.4||10.8||(15.1 predicted, -2.0)|
|2006.04||89.0||30.2||(14.4 predicted, -0.7)|
|2006.05||80.9||22.2||(13.5 predicted, -0.9)|
|2006.06||75.9 (1)||22.0 (2)||(11.4 predicted, -2.1)|
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% lower.
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.