Last major update issued on August 12, 2005 at 04:50 UTC. First cycle 24 REGION observed
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The geomagnetic field was quiet on August 11. Solar wind speed ranged between 347 and 450 (all day average 406) km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 75.6. The planetary
index was 6 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 11212222 (planetary), 21222222 (Boulder).
The background x-ray flux is at the class A3 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 10794 decayed slowly and quietly. The region is about to rotate over the southwest limb.
Region 10795 developed slowly and was quiet.
New region 10797 became visible near the southeast limb on August 10 and was numbered the next day by SEC. The region developed slowly on August 11.
Comment added at 23:50 UTC on August 12: The first solar cycle 24 region emerged today in the northeast quadrant. Its location at 17h UTC was N27E32. Polarities are reversed compared to cycle 23 polarities and the high latitude location makes it unlikely that the region belongs to cycle 23.
August 9-11: No obvious partly or fully Earth directed CMEs were observed.
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 poorly defined trans equatorial coronal (CH180) was in an Earth facing position on August 8-9. Recurrent trans equatorial coronal hole (CH181) will likely rotate to an Earth facing position on August 13-15.
Processed SOHO/EIT 284 image at 01:06 UTC on August 12. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet on August 12-15, possibly with a few unsettled intervals on August 12 should any effects from CH180 arrive. A high speed stream from CH181 is likely to arrive on August 16 and cause unsettled to minor storm conditions until August 18.
|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 very poor. Propagation on long distance northeast-southwest paths is good to very good. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and LT28 Rafaela Argentina. Very impressive signals were noted from 1030 Radio del Plata, 1190 Radio América, 710 Radio Diez, 1270 Radio Provincia de Buenos Aires (all Argentina). Lots of other stations from Argentina and Uruguay were heard on other frequencies throughout the MW band.
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|
|10794||2005.07.31||2||2||S14W76||0140||HAX||area was 0090 at midnight|
classification was CAO at midnight
formerly region S579
|Total spot count:||5||8|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2005.02||97.2||29.2||(33.5 predicted, -1.1)|
|2005.03||89.9||24.5||(32.1 predicted, -1.4)|
|2005.04||86.0||24.4||(30.2 predicted, -1.9)|
|2005.05||99.3||42.6||(27.6 predicted, -2.6)|
|2005.06||93.7||39.6||(26.1 predicted, -1.5)|
|2005.07||96.4||39.9||(25.1 predicted, -1.0)|
|2005.08||94.7 (1)||24.9 (2)||(23.2 predicted, -1.9)|
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% 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.