Last major update issued on October 17, 2006 at 03:30 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update October 2, 2006)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 2, 2006)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October 2, 2006)]
[Historical solar and geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update October 2, 2006)]
The geomagnetic field was quiet to unsettled on October 16. Solar wind speed ranged between 387 and 467 km/s (all day average 444 km/s - decreasing 102 km/s from the previous day), slowly decreasing all day.
Solar flux measured at 20h UTC on 2.8 GHz was 69.5. The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 7.5). Three hour interval K indices: 32211133 (planetary), 32322212 (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 14-16: 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 large, recurrent trans equatorial coronal hole (CH244) will rotate into an Earth facing position on October 16-18.
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 17-19. During the latter half of October 19 a high speed stream from CH244 will likely arrive and cause unsettled to major storm conditions until October 21 or 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 to occasionally fair. Propagation on long distance northeast-southwest paths is poor.
Monitoring remarks from a location near N58E05: In addition to the regular Newfoundland and New York stations, quite a few stations from Nova Scotia, New Brunswick and northeastern US were noted with fair signals. 1470 WLAM was quite good in peaks. Stations from further south, from the Caribbean and from Venezuela and Colombia, were more numerous than during the previous night.
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
|Location at midnight||Area||Classification||Comment|
|Total spot count:||0||0|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|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||74.9 (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.