Last major update issued on February 11, 2005 at 04:35 UTC.
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The geomagnetic field was quiet to active on February 10. Solar wind speed ranged between 606 and 866 km/sec under the influence of a high speed stream from CH144. The high speed stream is about to end as wind speed has been decreasing steadily since noon on February 10.
Solar flux measured at 20h UTC on 2.8 GHz was 114.1. The planetary
A
index was 17 (STAR Ap - based on the mean of three hour interval ap
indices: 17.0).
Three hour interval K indices: 44334232 (planetary), 43343333 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 6 spotted regions on the visible solar disk. The solar flare activity level was low. A single C class event was recorded during the day.
Region 10730 was quiet and stable.Spotted regions not numbered by NOAA/SEC:
[S509] This region emerged in the southeast quadrant early on February 9 with a few small spots. Location at midnight:
S05W05.
February 8-10: No obvious 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 (CH145) in the northern hemisphere will likely rotate to a geoeffective position on February 14.
Processed SOHO/EIT 284 image at 01:06 UTC on February 11. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on February 10 due to a high speed stream from CH144. Quiet to unsettled is likely on February 11-13.
| 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 poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración with a fair to good signal. Most of the other trans Atlantic signals were from the easternmost parts of the US and Canada. The best signals were noted from WWRU on 1660 kHz and WWZN on 1510 kHz.
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 |
|---|---|---|---|---|---|---|---|
| 10730 | 2005.02.04 | 2 | 2 | S20W05 | 0050 | HAX | |
| 10731 | 2005.02.06 | S02W25 | plage | ||||
| 10732 | 2005.02.06 | 6 | 8 | 0040 | DRO |
classification was BXI at midnight, area 0020 location: N09E07 |
|
| 10733 | 2005.02.07 | 3 | 3 | S08E40 | 0310 | CHO |
classification was HKX at midnight |
| 10734 | 2005.02.09 | 1 | 1 | S04E57 | 0050 | HAX | classification was HSX at midnight |
| 10735 | 2005.02.10 | 1 | 3 | S08E74 | 0080 | HSX |
formerly region S510 classification was HAX at midnight, area 0180 |
| S509 | emerged on 2005.02.09 |
2 | S07W05 | 0010 | AXX | ||
| Total spot count: | 13 | 19 | |||||
| SSN: | 63 | 79 | |||||
| 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) |
| 2003.12 | 114.9 | 46.5 | 54.8 (-1.9) |
| 2004.01 | 114.1 | 37.3 | 52.0 (-2.8) |
| 2004.02 | 107.0 | 45.8 | 49.3 (-2.7) |
| 2004.03 | 112.0 | 49.1 | 47.1 (-2.2) |
| 2004.04 | 101.2 | 39.3 | 45.5 (-1.6) |
| 2004.05 | 99.8 | 41.5 | 43.9 (-1.6) |
| 2004.06 | 97.4 | 43.2 | 41.7 (-2.2) |
| 2004.07 | 119.1 | 51.0 | 40.3 (-1.4) |
| 2004.08 | 109.6 | 40.9 | (38.9 predicted, -1.4) |
| 2004.09 | 103.1 | 27.7 | (36.6 predicted, -2.3) |
| 2004.10 | 105.9 | 48.4 | (34.4 predicted, -2.2) |
| 2004.11 | 113.2 | 43.7 | (32.5 predicted, -1.9) |
| 2004.12 | 94.5 | 17.9 | (30.2 predicted, -2.3) |
| 2005.01 | 102.2 | 31.3 | (27.6 predicted, -2.6) |
| 2005.02 | 95.6 (1) | 16.3 (2) | (25.2 predicted, -2.4) |
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% less.
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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