Solar Terrestrial Activity Report

Last major update issued on November 2, 2006 at 04:50 UTC. The next update will be on November 6 as I will be at the annual DXLC board meeting this weekend.

[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 on November 1. Solar wind speed ranged between 350 and 407 km/s (all day average 375 km/s - decreasing 25 km/s from the previous day)..

Solar flux measured at 20h UTC on 2.8 GHz was 86.7. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 5.5). Three hour interval K indices: 21112122 (planetary), 12222221 (Boulder).

The background x-ray flux is at the class B1 level.

At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.

Region 10921 developed quickly and became more complex as negative polarity flux emerged near the trailing positive polarity spots. C flares are possible and there is a chance of a minor M class flare.
Region 10922 developed slowly and quietly.

Spotted regions not numbered by NOAA/SEC:
[S679] This region emerged in the southwest quadrant on November 1. Location at midnight: S09W58

Coronal mass ejections (CMEs)

October 30 - November 1: No obvious partly or fully Earth directed CMEs were detected in 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

Recurrent coronal hole CH246 in the northern hemisphere was in an Earth facing position on October 30-31. Recurrent trans equatorial coronal hole CH247 will rotate into an Earth facing position on November 6-8.

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 to unsettled on November 2-3 with a chance of active intervals due to effects from CH246. Quiet conditions are likely on November 4-8 while another disturbance with quiet to active conditions is expected on November 9-11 as the high speed stream from CH247 becomes geoeffective.

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: There was little change from the previous night. Most of the audible stations were from the east coast of North America, the Caribbean and from the northwestern part of South America.

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
10919 2006.10.27     S15W67     plage
10921 2006.10.31 22 33 S07E30 0270 EAI beta-gamma
area was 0350 at midnight
10922 2006.10.31 4 10 S14E44 0040 CSO classification was DAO at midnight, area 0060
S679 2006.11.01   3 S09W58 0020 CRO  
Total spot count: 26 46  
SSN: 46 76  

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 86.7 (1) 1.5 (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.


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