Last major update issued on February 9, 2006 at 04:45 UTC. The next update will be posted on February 13.
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The geomagnetic field was inactive to quiet on February 8. Solar wind speed ranged between 272 and 374 (all day average 307) km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 74.0. The planetary A
index was 3 (STAR Ap - based on the mean of three hour interval ap
indices: 3.1).
Three hour interval K indices: 20211000 (planetary), 21411100 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
New region 10852 emerged in the southeast quadrant on February 7 and was numbered the next day by NOAA/SEC.
Spotted regions not numbered by NOAA/SEC:
[S622] This region emerged in the southwest quadrant on February 8. Location at midnight:
S10W36.
February 6-8: No obviously fully or partly Earth directed CMEs were observed.
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 coronal hole (CH210) in the northern hemisphere was in an Earth facing position on February 8.
Processed SOHO/EIT 284 image at 01:06 UTC on February 9. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet on February 9-10, becoming quiet to unsettled on February 11-12 due to effects from CH210.
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 poor. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). Propagation was poorer than expected with only the most usual stations from North America audible.
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 spot count |
STAR spot count |
Location at midnight | Area | Classification | Comment |
---|---|---|---|---|---|---|---|
10852 | 2006.02.08 | 2 | 2 | S10W04 | 0010 | HSX | formerly region S621 |
S620 | 2006.02.04 | N05W55 | plage | ||||
S622 | 2006.02.08 | 2 | S10W36 | 0020 | HSX | ||
Total spot count: | 2 | 4 | |||||
SSN: | 12 | 24 |
Month | Average solar flux at Earth |
International sunspot number | Smoothed sunspot number |
---|---|---|---|
2000.04 | 184.2 | 125.5 | 120.8 cycle 23 sunspot max. |
2000.07 | 202.3 | 170.1 | 119.8 |
2001.12 | 235.1 | 132.2 | 114.6 (-0.9) |
2004.12 | 94.5 | 17.9 | 35.2 (-0.1) |
2005.01 | 102.2 | 31.3 | 34.6 (-0.6) |
2005.02 | 97.2 | 29.2 | 33.9 (-0.7) |
2005.03 | 89.9 | 24.5 | 33.5 (-0.4) |
2005.04 | 86.0 | 24.4 | 31.6 (-1.9) |
2005.05 | 99.3 | 42.6 | 28.9 (-2.7) |
2005.06 | 93.7 | 39.6 | 28.8 (-0.1) |
2005.07 | 96.4 | 39.9 | 29.1 (+0.3) |
2005.08 | 90.5 | 36.4 | (27.6 predicted, -1.5) |
2005.09 | 91.1 | 22.1 | (25.8 predicted, -1.8) |
2005.10 | 77.0 | 8.5 | (24.0 predicted, -1.8) |
2005.11 | 86.3 | 18.0 | (21.6 predicted, -2.4) |
2005.12 | 90.7 | 41.2 | (18.7 predicted, -2.9) |
2006.01 | 83.4 | 15.4 | (15.6 predicted, -3.1) |
2006.02 | 76.2 (1) | 0.4 (2) | (12.5 predicted, -3.1) |
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.
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