Solar Terrestrial Activity Report

Last major update issued on November 24, 2005 at 05:55 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 9, 2005)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 9, 2005)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 9, 2005)]
[Historical solar and geomagnetic data charts 1954-2004 (last update February 1, 2005)]
[Archived reports (last update November 2, 2005)]

Recent activity

The geomagnetic field was quiet to unsettled on November 23. Solar wind speed ranged between 308 and 476 (all day average 368) km/sec under the influence of a weak low speed stream from CH199.

Solar flux measured at 20h UTC on 2.8 GHz was 89.7. The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 8.1)
Three hour interval K indices: 13322212 (planetary), 03323212 (Boulder).

The background x-ray flux is at the class A6 level.

At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events was recorded during the day.

Region 10822 decayed significantly and lost the trailer spots.
Region 10824 decayed slowly and quietly.

Coronal mass ejections (CMEs)

November 21-23: No obvious fully or partly Earth directed CMEs were observed. A complex full halo CME was observed on Nov.21, its origin was most likely backsided.

Coronal holes

Coronal hole history (since late October 2002)
Compare today's report with the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

The northernmost extension of a southern hemisphere coronal hole (CH199) was in a potentially geoeffective position on November 20. Another extension of the same coronal hole was in an facing position on November 23.

Processed SOHO/EIT 284 image at 19:06 UTC on November 23. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 24-26.

Coronal holes (1) Coronal mass ejections (2) M and X class flares (3)
Coronal hole indicator CME indicator M and X class flare indicator

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) Material from a CME is likely to impact 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. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). Quite a few stations from the easternmost parts of the USA and Canada were heard at weak to fair levels.

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
10822 2005.11.12 6 6 S07W63 0320 EKO classification was DKO at midnight
10824 2005.11.20 9 7 S14E32 0090 DAO  
S606 2005.11.19     S10W17     plage
Total spot count: 15 13  
SSN: 35 33  

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)
2004.09 103.1 27.7 37.5 (-1.7)
2004.10 105.9 48.0 35.9 (-1.6)
2004.11 113.2 43.5 35.3 (-0.6)
2004.12 94.5 17.9 35.2 (-0.1)
2005.01 102.2 31.3 34.6 (-0.6)
2005.02 97.2 29.2 33.9 (-0.7)
2005.03 89.9 24.5 33.5 (-0.4)
2005.04 86.0 24.4 31.6 (-1.9)
2005.05 99.3 42.6 (28.9 predicted, -2.7)
2005.06 93.7 39.6 (27.3 predicted, -1.6)
2005.07 96.4 39.9 (26.1 predicted, -1.2)
2005.08 90.5 36.4 (24.3 predicted, -1.8)
2005.09 91.1 22.1 (22.2 predicted, -2.1)
2005.10 77.0 8.5 (20.2 predicted, -2.0)
2005.11 86.9 (1) 24.3 (2) (17.8 predicted, -2.4)

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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