Last major update issued on October 7, 2007 at 03:00 UTC.
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The geomagnetic field was quiet on October 6. Solar wind speed ranged between 345 and 408 km/s (average speed was 365 km/s, decreasing 78 km/s from the previous day).
Solar flux measured at 20h UTC on 2.8 GHz was 69.0. The planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.0). Three hour interval K indices: 10122212 (planetary), 11222111 (Boulder).
The background x-ray flux is below the class A1 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.
New region 10972 emerged in the southeast quadrant on October 5 and was numbered trhe next day by NOAA/SWPC. The region decayed slightly on October 6 as polarity separation increased.
October 4-6: No obvious fully or partly Earth directed CMEs were observed in LASCO imagery.
Coronal hole
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 (CH294) in the southern hemisphere could rotate into an Earth facing position on October 8.
Processed STEREO-B 195 image at 21:45 UTC on October 6. The darkest areas on the solar disk are likely coronal holes.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over high and upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is fair.
Monitoring remarks from a location near N58E06: October 6: Only a few of the most common signals from North America were audible during the night. The best signals were heard from stations in Colombia, Venezuela, Cuba and Puerto Rico. 1470 kHz had many stations and it was difficult to get proper IDs. Colombian Ondas de Ibagué was one of the better signals. The best Trans Atlantic propagation sector was 255-265 degrees.
The geomagnetic field is expected to be generally quiet October 7-16. A few unsettled intervals are possible on October 11-12 due to effects from CH294.
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.
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 |
---|---|---|---|---|---|---|---|
10972 | 2007.10.06 | 5 | 6 | S05W06 | 0060 | CRO | formerly region S709 classification was DSO at midnight |
Total spot count: | 5 | 6 | |||||
SSN: | 15 | 16 |
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) |
2006.08 | 79.0 | 12.9 | 15.6 (+0.3) |
2006.09 | 77.8 | 14.4 | 15.6 (+0.0) |
2006.10 | 74.3 | 10.4 | 14.2 (-1.4) |
2006.11 | 86.3 | 21.5 | 12.7 (-1.5) |
2006.12 | 84.5 | 13.6 | 12.1 (-0.6) |
2007.01 | 83.3 | 16.9 | 12.0 (-0.1) |
2007.02 | 77.7 | 10.6 | 11.6 (-0.4) |
2007.03 | 72.2 | 4.8 | 10.8 (-0.8) |
2007.04 | 72.4 | 3.7 | (10.1 predicted, -0.7) |
2007.05 | 74.4 | 11.7 | (9.0 predicted, -1.1) |
2007.06 | 73.7 | 12.0 | (8.0 predicted, -1.0) |
2007.07 | 71.6 | 10.0 | (7.3 predicted, -0.7) |
2007.08 | 69.1 | 6.2 | (6.8 predicted, -0.5) |
2007.09 | 67.1 | 2.4 | (6.9 predicted, +0.1) |
2007.10 | 67.6 (1) | 0.9 (2) | (7.6 predicted, +0.7) |
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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