Solar Terrestrial Activity Report

Last major update issued on November 11, 2003 at 04:45 UTC. Minor update posted at 17:34 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, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 4, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 4, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update November 5, 2003)]

Recent activity

The geomagnetic field was active to minor storm on November 10. Solar wind speed ranged between 449 and 710 km/sec under the influence of high speed streams from coronal holes CH65 and CH66. Solar wind speed had been decreasing slowly until about 11h UTC. Then a strong high speed stream from coronal hole CH66 arrived (one day earlier than expected) and wind speed increased slowly for the remainder of the day.

Solar flux measured at 20h UTC on 2.8 GHz was 94.6. The planetary A index was 30 (STAR Ap - based on the mean of three hour interval ap indices: 29.5).
Three hour interval K indices: 44455444 (planetary), 44444444 (Boulder).

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

At midnight there were 3 spotted regions on the visible disk. Solar flare activity was low. A total of 2 C class events were recorded during the day. An impulsive, optically uncorrelated C1.9 flare occurred at 21:29 UTC.

Region 10498 developed slowly and has been producing a fair amount of low level activity. A weak magnetic delta structure has formed in the northern part of the trailing penumbra.
Region 10499 decayed slowly and quietly.
Region 10500 developed slowly early in the day, then began to decay. Flare: C1.5 at 20:14 UTC.

Comment added at 17:34 UTC on November 11: Region 10498 produced an M1.6 long duration event peaking at 13:51 UTC. A fairly large partial halo CME was associated with this event. Old region 10484 is getting close to the southeast limb and should rotate into view within 2-3 days. Today this region was the likely source of a long duration C8.5 event peaking at 16:17 UTC. A CME was observed off of the southeast limb.

Coronal mass ejections (CMEs)

November 9: A fast full halo CME was observed in LASCO C3 images beginning at 06:42 UTC. Material distribution indicates that old region 10484, a few days behind the southeast limb, was the source.

November 8 and 10: No partly or fully 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

A well defined recurrent trans equatorial coronal hole (CH66) will be in a geoeffective position on November 9-14.

Processed SOHO/EIT 284 image at 19:06 UTC on November 10. The darkest areas on the solar disk are likely coronal holes.


The geomagnetic field is expected to be minor to severe storm on November 11-12 and unsettled to minor storm on November 13-17 due to a high speed stream from coronal hole CH66.

Long distance low 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 very poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station: Radio Cristal del Uruguay occasionally noted with a weak signal].

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.
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.

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.

Solar region Date numbered SEC
Location at midnight Area Classification Comment
10498 2003.11.08 7 10 S04W49 0120 DAO beta-gamma-delta
10499 2003.11.08 3 3 S17W46 0050 DSO  
10500 2003.11.09 7 7 S09W36 0040 CSO  
Total spot count: 17 20
SSN: 47 50

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)
2002.10 167.0 97.5 90.5 (-4.1)
2002.11 168.7 95.5 85.2 (-5.3)
2002.12 157.2 80.8 82.0 (-3.2)
2003.01 144.0 79.7 80.9 (-1.1)
2003.02 124.5 46.0 78.5 (-2.4)
2003.03 131.4 61.1 74.1 (-4.4)
2003.04 126.4 60.0 70.3 (-3.8)
2003.05 115.7 55.2 (66.8 predicted, -3.5)
2003.06 129.3 77.4 (63.0 predicted, -3.8)
2003.07 127.7 85.0 (59.3 predicted, -3.7)
2003.08 122.1 72.7 (56.3 predicted, -3.0)
2003.09 112.2 48.8 (54.3 predicted, -2.0)
2003.10 151.7 65.6 (51.6 predicted, -2.7)
2003.11 131.9 (1) 26.1 (2) (48.9 predicted, -2.7)

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 sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.

[DX-Listeners' Club]