Last major update issued on February 7, 2007 at 05:20 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)
[Solar cycles 21-23 (last update January 11, 2007)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 11, 2007)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update January 11, 2007)]
[Historical solar and geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update February 6, 2007)]
The geomagnetic field was quiet to unsettled on February 6. Solar wind speed ranged between 340 and 440 km/s (average speed was 375 km/s, increasing 31 km/s over the previous day). A weak, low speed coronal stream has influenced the geomagnetic field since 10 UTC on February 5.
Solar flux measured at 20h UTC on 2.8 GHz was 81.7. The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.1). Three hour interval K indices: 13331011 (planetary), 12321002 (Boulder).
The background x-ray flux is at the class A1 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 10940 decayed slowly and quietly.
Region 10941 was quiet and stable.
Spotted regions not numbered by NOAA/SEC:
[S693] This region emerged in the southwest quadrant on February 6. Location at midnight: S03W60
February 4-6: 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
A recurrent coronal hole (CH257) in the southern hemisphere has lost most of its area over the last solar rotation due to the development of an active (and currently spotless) region. CH257 will likely rotate into an Earth facing position on February 8-9.
Processed SOHO/EIT 195 image at 00:00 UTC on February 7. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on February 7 and quiet on February 8-10. Effects from CH257 could reach Earth on February 11-12 and cause unsettled to active conditions.
|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.
Daily monitoring will not resume until a local noise problem (related to construction work on a neighboring property) has been fixed. Occasional monitoring reports will be submitted when propagation is good.
February 7, 2007: Several strong signal from North America (particularly from stations on Newfoundland and from in and near New York) were heard in the lower half of the MW band during the night. Signals are, in general, much better than they were about a month ago.
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|
|10940||2007.01.25||2||1||S05W71||0130||CSO||classification was HSX at midnight, area 0100|
|10941||2007.01.29||1||1||S07W35||0190||HSX||area was 0120 at midnight|
|Total spot count:||3||3|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2006.08||79.0||12.9||(15.6 predicted, +0.3)|
|2006.09||77.8||14.5||(15.7 predicted, +0.1)|
|2006.10||74.3||10.4||(14.5 predicted, -1.2)|
|2006.11||86.3||21.5||(12.8 predicted, -1.7)|
|2006.12||84.5||13.6||(12.1 predicted, -0.7)|
|2007.01||83.3||16.9||(12.0 predicted, -0.1)|
|2007.02||86.0 (1)||6.4 (2)||(12.1 predicted, +0.1)|
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.