Solar Terrestrial Activity Report

Last major update issued on November 3, 2003 at 04:30 UTC. Minor update posted at 10:20 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update October 4, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 4, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October 4, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update October 30, 2003)]

Recent activity

The geomagnetic field was unsettled to active on November 2. Solar wind speed ranged between 469 and 624 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 190.4. The planetary A index was 18 (STAR Ap - based on the mean of three hour interval ap indices: 19.0).
Three hour interval K indices: 34333443 (planetary), 35243542 (Boulder).

The background x-ray flux is at the class C2 level. A new proton storm started after the X8 flare mentioned below, the above 10 MeV proton flux has so far peaked near the 1500 pfu level.

At midnight there were 5 spotted regions on the visible disk. Solar flare activity was high. A total of 5 C, 3 M and 1 X class events was recorded during the day.

Region 10486 decayed significantly losing penumbral area in the trailing and central sections. Further major flares are possible as the region is still complex. Flares: C4.0 at 02:43, M1.0 at 07:53, C8 at 16:12, X8.3/2B at 17:25 UTC.
Region 10487 decayed slowly and was mostly quiet. Flare: C3.2 at 04:42 UTC.
Region 10488 decayed slightly in the trailing spot section while becoming more compact in the central and leading sections. Another X class flare is possible. Flares: C3.4 at 09:00, M1.8 at 12:47, C5 at 14:39, M1.3 at 19:30 UTC. This region was the source of an X2.7/2B flare at 01:30 UTC on November 3.
Region 10495 decayed slightly in the trailing spot section and was quiet.

Spotted regions not numbered by NOAA/SEC:
[S296] A new region emerged in the southeast quadrant on November 1. Location at midnight: S07E13.

Comment added at 10:20 UTC: Region 10488 produced its second X class flare of the day, an X3.9 event at 09:55 UTC. While it is possible for CMEs originating from a source near the limbs to reach the Earth, it is not likely that the CMEs associated with today's major flares in region 10488 will have any significant effects at Earth. Further major flares from this region will increase the likelihood of proton flares.

Coronal mass ejections (CMEs)

November 2: A fast and large full halo CME was observed after the X8 flare in region 10486. The CME could reach Earth late on November 3.

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

No obvious coronal holes are currently approaching geoeffective positions.

Processed SOHO/EIT 284 image at 01:10 UTC on November 3. Image quality is degraded because of a proton storm. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be unsettled to active until late on November 3. Then another strong CME impact is expected with active to major geomagnetic storming for about 24 hours after the impact.

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 poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station: Radio Cristal del Uruguay].

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
spot
count
STAR
spot
count
Location at midnight Area Classification Comment
10486 2003.10.22 60 54 S17W62 2160 FKC gamma-delta
area was 1500
at midnight
10487 2003.10.25 15 10 N12W34 0080 DAO  
10488 2003.10.27 23 19 N08W68 1600 FKC beta-gamma-delta
10489 2003.10.27 3   S12W76 0050 CSO spotless
10490 2003.10.27     S12W53     plage
10491 2003.10.27 2   S08W71 0030 AXX plage
10494 emerged on
2003.10.29
    S23W31     formerly region S295
plage
10495 2003.10.30 11 8 S22W21 0130 DSO formerly region S293
10496 2003.10.31     S12W17     plage
S294 emerged on
2003.10.29
    S09W07     plage
S296 emerged on
2003.11.01
  1 S07E13 0010 AXX  
Total spot count: 114 92
SSN: 174 142

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)
2002.09 175.8 109.6 94.6 (-4.1)
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 (69.6 predicted, -4.5)
2003.05 115.7 55.2 (65.3 predicted, -4.3)
2003.06 129.3 77.4 (61.5 predicted, -3.8)
2003.07 127.7 85.0 (58.0 predicted, -3.5)
2003.08 122.1 72.7 (55.0 predicted, -3.0)
2003.09 112.2 48.8 (53.0 predicted, -2.0)
2003.10 151.7 119.3 (2) (50.3 predicted, -2.7)
2003.11 200.4 (1) 15.0 (2)  

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.


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