Solar Terrestrial Activity Report

Last major update issued on November 22, 2004 at 03:25 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 minor storm on November 21. Solar wind speed ranged between 489 and 627 km/sec, mainly under the influence of a coronal hole high speed stream.

Solar flux measured at 20h UTC on 2.8 GHz was 100.9. The planetary A index was 16 (STAR Ap - based on the mean of three hour interval ap indices: 16.1).
Three hour interval K indices: 21354322 (planetary), 21354322 (Boulder).

The background x-ray flux is at the class B2 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 was recorded during the day.

Region 10701 decayed slowly and quietly.
Region 10704 developed slowly and was quiet.

Spotted regions not numbered by NOAA/SEC:
[S477] This region was first observed on November 14, then lost its spots. A single spot became visible on Nov. 21. Location at midnight: S04W40.

Coronal mass ejections (CMEs)

November 19-21: 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 will rotate into a geoeffective position on November 21-23.

Processed SOHO/EIT 284 image at 01:06 UTC on November 22. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on November 22-24.

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 very poor. Propagation along long distance north-south paths is poor to very poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay with a weak signal. The best signal from a trans Atlantic station was on 1620 kHz where WDHP was easily audible.

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
10701 2004.11.11 1 1 S15W61 0030 HSX area was 0020
at midnight
10702 2004.11.17     S09W85     plage
10703 2004.11.18     N12E08     plage
10704 2004.11.18 6 8 N12E39 0090 DSO  
S475 emerged on
2004.11.12
    S15W88     plage
S477 emerged on
2004.11.14
  1 S04W40 0000 AXX  
S480 visible on
2004.11.19
    S12E57     plage
Total spot count: 7 10
SSN: 27 40

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)
2004.11 114.8 (1) 54.5 (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]