Solar Terrestrial Activity Report

Last major update issued on November 9, 2004 at 04:20 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 8, 2004)]

Recent activity

The geomagnetic field was unsettled to extremely severe storm on November 8. Solar wind speed ranged between 553 and 928 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 136.4. The planetary A index was 189 (STAR Ap - based on the mean of three hour interval ap indices: 188.9).
Three hour interval K indices: 99986345 (planetary), 88876334 (Boulder).

The background x-ray flux is at the class C1 level.

At midnight there were 4 spotted regions on the visible solar disk. The solar flare activity level was moderate. A total of 6 C and 1 M class events was recorded during the day.

Region 10693 rotated partly out of view at the southwest limb. Flare: C1.0 at 16:44 UTC.
Region 10696 decayed further but remains a very complex region with multiple magnetic delta structures. A major flare is still possible. Flares: very long duration C6 event beginning at 02h and peaking at 04:32 (associated with a weak type IV radio sweep and a full halo CME. EIT images show a large filament eruption), C7.9 at 03:29 (superimposed on the LDE, origin at a different location in the region), C1.8 at 08:38, C7.7/1N at 14:35 and M2.3/1N at 15:49 UTC.
Region 10698 developed slowly adding several small spots. Flare: C1.6 at 21:31 UTC.

Coronal mass ejections (CMEs)

November 8: A full halo CME was observed early in the day after a long duration event in the eastern part of region 10696. This CME will probably reach Earth late on November 10 or on November 11.
November 7:
A large and fast full halo CME was observed after the X2 flare in region 10696 during the afternoon. This CME will likely reach Earth before noon on November 9.

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

Trans equatorial coronal hole CH125 was in a geoeffective position on November 8, however, most of this coronal hole closed after the long duration event in region 10696 early in the day.

Processed SOHO/EIT 284 image at 01:06 UTC on November 9. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be at minor to very severe storm levels on November 9 due to a CME impact. Unsettled to major storm is likely on November 10 becoming active to major storm on November 11 due to another CME impact.

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 useless. 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 stations tonight: none, only a carrier was noted. On other frequencies a few stations from Brazil could be heard with weak signals (740, 760, 1130, 1430 and 1600 kHz).

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
10693 2004.10.27 3 3 S17W82 0120 HAX  
10695 2004.10.30     S16W53     plage
10696 2004.11.01 48 31 N08W36 0600 EKC beta-gamma-delta
10697 2004.11.06     N05W78     plage
10698 2004.11.06 12 23 S09W72 0150 DAI  
S470 emerged on
2004.11.06
    N05W02     plage
S471 emerged on
2004.11.08
  2 N04E36 0010 BXO  
Total spot count: 63 59
SSN: 93 99

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)
2004.11 134.6 (1) 29.6 (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.


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