Last major update issued on May 9, 2007 at 03:40 UTC.
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The geomagnetic field was quiet to active on May 8. Solar wind speed ranged between 532 and 634 km/s (average speed was 575 km/s, increasing 203 km/s over the previous day) under the influence of a high speed stream from CH268.
Solar flux measured at 20h UTC on 2.8 GHz was 73.2. The planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 13.6). Three hour interval K indices: 24422233 (planetary), 25433322 (Boulder).
The background x-ray flux is at the class A4 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. An active region at the east limb could rotate into view today.
Spotted regions not numbered by NOAA/SEC:
[S701] This region emerged on May 8 in the southeast quadrant.
Polarity separation is currently poor and occasional C flares are possible.
Location at midnight: S09E35.
May 6-8: No obvious fully or partially 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
No obvious coronal holes are currently in or approaching an Earth facing position.
Processed SOHO/EIT 195 image at 19:13 UTC on May 8. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be mostly quiet on May 9-13.
| 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) 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.
April 8, 2007: Stations from the Canadian Atlantic provinces had strong signals during the night. Some stations from the northeastern USA and from Florida did well too, in particular 1510 WWZN was impressive.
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 |
|---|---|---|---|---|---|---|---|
| 10953 | 2007.04.25 | 2 | S11W98 | 0090 | AXX | rotated out of view | |
| 10954 | 2007.04.30 | S07W77 | plage | ||||
| S701 | 2007.05.08 | 5 | S09E35 | 0020 | DRO | ||
| Total spot count: | 2 | 5 | |||||
| SSN: | 12 | 15 | |||||
| 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) |
| 2006.02 | 76.5 | 4.9 | 18.6 (-2.2) |
| 2006.03 | 75.4 | 10.6 | 17.4 (-1.2) |
| 2006.04 | 89.0 | 30.2 | 17.1 (-0.3) |
| 2006.05 | 80.9 | 22.3 | 17.3 (+0.2) |
| 2006.06 | 76.5 | 13.9 | 16.3 (-1.0) |
| 2006.07 | 75.7 | 12.2 | 15.3 (-1.0) |
| 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 | (12.4 predicted, -1.8) |
| 2006.12 | 84.5 | 13.6 | (11.3 predicted, -1.1) |
| 2007.01 | 83.3 | 16.9 | (10.6 predicted, -0.7) |
| 2007.02 | 77.7 | 10.6 | (10.3 predicted, -0.3) |
| 2007.03 | 72.2 | 4.8 | (10.3 predicted, +0.0) |
| 2007.04 | 72.4 | 3.7 | (10.8 predicted, +0.5) |
| 2007.05 | 80.9 (1) | 5.6 (2) | (10.9 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.
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