Solar Terrestrial Activity Report

Last major update issued on November 21, 2005 at 04:50 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 20. Solar wind speed ranged between 346 and 427 (all day average 381) km/sec under the influence of a low speed stream from CH198.

Solar flux measured at 20h UTC on 2.8 GHz was 96.4. The planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 6.8)
Three hour interval K indices: 12321212 (planetary), 12321211 (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 low. A total of 2 C class events was recorded during the day.

Region 10822 decayed slowly as several spots in the intermediate spot section disappeared. Flares: C2.5 at 07:36 and C1.5 at 15:20 UTC.
Region 10823 decayed and could soon become spotless.
New region 10824 rotated into view on Nov.19 and was numbered by NOAA/SEC the following day. The region could produce C flares.

Coronal mass ejections (CMEs)

November 17-19: No obvious fully or partly Earth directed CMEs were observed.

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.

Processed SOHO/EIT 284 image at 01:06 UTC on November 21. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet on November 21-22 and quiet to active on November 23 due to coronal hole effects.

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 fair to good. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: WWNN Pompano Beach FL. On other frequencies stations from Cuba and Florida (790 WAXY, 850 WFTL a.o.) had the best signals.

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 22 14 S08W25 0570 FKI classification was FKO at midnight
10823 2005.11.19 3 3 S17W50 0040 DSO classification was CRO at midnight, area 0010
10824 2005.11.20 1 5 S13E68 0090 HAX formerly region S607
classification was CAO at midnight, area 0120
S606 2005.11.19     S10E22     plage
Total spot count: 26 22  
SSN: 56 52  

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 86.1 (1) 20.4 (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.


[DX-Listeners' Club]