Last major update issued on October 16, 2006 at 02:25 UTC.
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October 2, 2006)]
The geomagnetic field was quiet to unsettled on October 15. Solar wind speed ranged between 466 and 607 km/s (all day average 546 km/s - increasing 26 km/s over the previous day) under the influence of a high speed stream from CH243.
Solar flux measured at 20h UTC on 2.8 GHz was 71.1. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 9.5). Three hour interval K indices: 33231112 (planetary), 44341222 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight the visible solar disk was spotless. The solar flare activity level was very low. No C class events were recorded during the day.
October 13-15: No obvious partly or fully Earth directed CMEs were detected 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 well defined recurrent trans equatorial coronal hole (CH244) will rotate into an Earth facing position on October 17-18.
Processed SOHO/EIT 284 image at 13:06 UTC on October 15. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be mostly quiet October 16-19. A high speed stream from CH244 could cause unsettled to major storm conditions starting late on October 19 or early on October 20 lasting until October 22.
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 and improving. Propagation on long distance northeast-southwest paths is poor.
Several stations from North America were audible at night. 780 CFDR, 790 WAXY, 930 CJYQ, 1130 WBBR and 1510 WWZN all had occasionally strong signals. Some stations from Cuba and Colombia were heard with fair signals.
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 |
---|---|---|---|---|---|---|---|
Total spot count: | 0 | 0 | |||||
SSN: | 0 | 0 |
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) |
2005.08 | 90.5 | 36.4 | 27.4 (-1.7) |
2005.09 | 91.1 | 21.9 | 25.8 (-1.6) |
2005.10 | 77.0 | 8.7 | 25.5 (-0.3) |
2005.11 | 86.3 | 18.0 | 24.9 (-0.6) |
2005.12 | 90.7 | 41.1 | 23.0 (-1.9) |
2006.01 | 83.4 | 15.3 | 20.8 (-2.2) |
2006.02 | 76.5 | 4.9 | 18.6 (-2.2) |
2006.03 | 75.4 | 10.6 | 17.3 (-1.3) |
2006.04 | 89.0 | 30.2 | (17.1 predicted, -0.2) |
2006.05 | 80.9 | 22.2 | (16.8 predicted, -0.3) |
2006.06 | 76.5 | 13.9 | (15.1 predicted, -1.7) |
2006.07 | 75.7 | 12.2 | (13.2 predicted, -1.9) |
2006.08 | 79.0 | 12.9 | (12.8 predicted, -0.4) |
2006.09 | 77.8 | 14.5 | (12.6 predicted, -0.2) |
2006.10 | 75.3 (1) | 7.6 (2) | (11.6 predicted, -1.0) |
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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