Solar Terrestrial Activity Report

Last major update issued on November 6, 2006 at 04:45 UTC.

[Solar and 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)]

Recent activity

The geomagnetic field was quiet to unsettled on November 5. Solar wind speed ranged between 343 and 418 km/s (all day average 368 km/s - decreasing 35 km/s from the previous day)..

Solar flux measured at 20h UTC on 2.8 GHz was 84.7. The planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 4.6). Three hour interval K indices: 01231101 (planetary), 01332210 (Boulder).

The background x-ray flux is at the class A5 level.

At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 2 C class events was recorded during the day.

Region 10921 decayed slowly and remains capable of producing occasional C flares. Flares: long duration C1.3 peaking at 07:51 and C3.7 at 12:27 UTC.
Region 10922 decayed slowly and quietly.

Coronal mass ejections (CMEs)

November 3-5: No obvious partly or fully Earth directed CMEs were detected in limited LASCO imagery.

Coronal holes

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 in the southern hemisphere, CH247, will rotate into an Earth facing position on November 6-7.

Processed SOHO/EIT 284 image at 01:06 UTC on November 2. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet on November 6-8 and become quiet to active on November 9-11 due to a high speed stream from CH247.

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.

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to fair. Propagation on long distance northeast-southwest paths is poor.

Monitoring remarks from a location near N58E06: No monitoring on November 6. On November 3 propagation didn't favour any particular area with stations from North America, the Caribbean and the northern parts of South America all heard at mostly fair signal levels. On November 4 propagation was very poor while November 5 saw a very fast recovery after the coronal hole disturbance. Lots of interesting stations were heard then including 1410 WMYR, 1420 WDJA and 1410 Radio Mensabé (Panamá).

Active solar regions (Recent map)

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
10921 2006.10.31 26 19 S08W24 0290 ESO  
10922 2006.10.31 16 7 S09W13 0090 CAO  
Total spot count: 42 26  
SSN: 62 46  

Monthly solar cycle data

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 (-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 (12.7 predicted, -0.5)
2006.09 77.8 14.5 (12.6 predicted, -0.1)
2006.10 74.3 10.4 (11.5 predicted, -1.1)
2006.11 86.5 (1) 9.2 (2) (10.1 predicted, -1.4)

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% 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.


[DX-Listeners' Club]