Solar Terrestrial Activity Report

Last major update issued on November 25, 2004 at 04:30 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 4, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 4, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 4, 2004)]
[Historical solar and geomagnetic data charts 1954-2004 (last update November 8, 2004)]
[Archived reports (last update November 20, 2004)]

Recent activity

The geomagnetic field was quiet to unsettled on November 24. Solar wind speed ranged between 364 and 457 km/sec. A fairly strong high speed stream from coronal hole CH128 arrived during the last hours of the day. A disturbance began during the first hour of November 25 and active to minor storm conditions are currently observed.

Solar flux measured at 20h UTC on 2.8 GHz was 107.3. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.5).
Three hour interval K indices: 21132212 (planetary), 22132212 (Boulder).

The background x-ray flux is at the class B3 level.

At midnight there were 5 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 4 C class events was recorded during the day.

Region 10704 decayed slowly and quietly.
Region 10705 developed slowly as it rotated to the southwest limb.
New region 10706 rotated into view at the southeast limb late on November 23 and was numbered the next day by SEC.
New region 10707 rotated partly into view at the southeast limb late on November 23 and was numbered by SEC the following day. While this region is fairly small, it has a complex magnetic field layout. There is negative polarity in the southwest and northwest and positive polarity in the north and in the southeast. Both polarities are present in the main penumbra creating a magnetic delta structure. M class flares are possible. Flares: C2.9 at 07:55, C5.9 at 08:34, C8.2 at 17:25, C9.8 at 21:45 UTC.

Spotted regions not numbered by NOAA/SEC:
[S483] A new region emerged in the southeast quadrant near the central meridian on November 24. Location at midnight: S09E00.

Coronal mass ejections (CMEs)

November 22-24: No obviously Earth directed CMEs 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

Recurrent coronal hole CH128 in the southern hemisphere was in a geoeffective position on November 21-23. Large and well defined recurrent trans equatorial coronal hole CH129 will rotate into a geoeffective position on November 27-28.

Processed SOHO/EIT 284 image at 01:06 UTC on November 25. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be unsettled to minor storm on November 25 and quiet to active on November 26-27. Quiet to unsettled is likely on November 28-29 becoming unsettled to major storm on November 30 when the high speed stream from coronal hole CH129 arrives.

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.


Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is very poor. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. On other frequencies signals were generally weak and from Brazilian stations. A single North American station, WWZN on 1510 kHz, was heard with a very weak signal.

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
Location at midnight Area Classification Comment
10703 2004.11.18 4   N13W31 0010 AXX spotless, no spots
observed at any time
during the day
10704 2004.11.18 7 4 N13W04 0090 DAO classification was CAO
at midnight
10705 2004.11.23 5 3 S04W80 0060 CAO  
10706 2004.11.24 5 7 S08E71 0080 DAO beta-delta
formerly region S482
location: S06E69
10707 2004.11.24 1 2 S16E68 0080 HAX formerly region S481
classification was CAO
at midnight
S483 visible on
  2 S09E00 0020 HRX  
Total spot count: 22 18
SSN: 72 68

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)
2003.08 122.1 72.7 60.0 (-1.7)
2003.09 112.2 48.7 59.5 (-0.5)
2003.10 151.7 65.5 58.2 (-1.3)
2003.11 140.8 67.3 56.7 (-1.5)
2003.12 114.9 46.5 54.8 (-1.9)
2004.01 114.1 37.3 52.0 (-2.8)
2004.02 107.0 45.8 49.3 (-2.7)
2004.03 112.0 49.1 47.1 (-2.2)
2004.04 101.2 39.3 45.5 (-1.6)
2004.05 99.8 41.5 (42.8 predicted, -2.7)
2004.06 97.4 43.2 (40.0 predicted, -2.8)
2004.07 119.1 51.0 (38.2 predicted, -1.8)
2004.08 109.6 40.9 (36.6 predicted, -1.6)
2004.09 103.1 27.7 (34.7 predicted, -1.9)
2004.10 105.9 48.4 (32.5 predicted, -2.2)
2004.11 113.8 (1) 59.4 (2) (31.0 predicted, -1.5)

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% less.

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]