Last major update issued on December 9, 2006 at 06:10 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 12, 2006)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 12, 2006)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 12, 2006)]
[Historical solar and geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update November 12, 2006)]
The geomagnetic field was unsettled to minor storm on December 8. Solar wind speed ranged between 488 and 734 km/s (all day average 576 km/s - decreasing 71 km/s from the previous day). Wind speed decreased slowly and gradually during the latter half of the day. A solar wind shock was observed at SOHO at 04:12 UTC when the CME associated with the X6.5 flare on December 6 arrived. No further CMEs are expected at this time.
Solar flux measured at 20h UTC on 2.8 GHz was 96.0. The planetary A index was 25 (STAR Ap - based on the mean of three hour interval ap indices: 24.6). Three hour interval K indices: 35353333 (planetary), 45453233 (Boulder).
The background x-ray flux is at the class A7 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Region 10930 has a weak magnetic delta structure in the southern part
of the single penumbra. There is still a chance of an M class flare.
December 7-8: No obvious partly or fully Earth directed CMEs were detected in LASCO imagery.
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
No obvious coronal holes are currently in or approaching Earth facing positions.
Processed SOHO/EIT 284 image at 19:06 UTC on November 24. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be mostly quiet on December 9-12.
|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 very poor.
Monitoring remarks from a location near N58E06: 1290 Radio Puerto Cabello (Venezuela) was noted with a fair to good signal. No other trans Atlantic stations reached more than a very poor signal level.
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|
|10927||2006.11.27||1||N08W88||0050||AXX||rotated out of view|
classification was DKC at midnight
|Total spot count:||12||7|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2006.06||76.5||13.9||(16.3 predicted, -1.0)|
|2006.07||75.7||12.2||(14.7 predicted, -1.6)|
|2006.08||79.0||12.9||(14.2 predicted, -0.5)|
|2006.09||77.8||14.5||(14.1 predicted, -0.1)|
|2006.10||74.3||10.4||(13.0 predicted, -1.1)|
|2006.11||86.3||21.5||(11.5 predicted, -1.5)|
|2006.12||94.0 (1)||12.4 (2)||(11.3 predicted, -0.2)|
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.