Solar Terrestrial Activity Report

Last major update issued on November 4, 2003 at 04:35 UTC. Minor update posted at 13:14 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 October 30, 2003)]

Recent activity

The geomagnetic field was quiet to unsettled on November 3. Solar wind speed ranged between 464 and 568 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 166.9. The planetary A index was 10 (STAR Ap - based on the mean of three hour interval ap indices: 11.5).
Three hour interval K indices: 33232323 (planetary), 33223323 (Boulder).

The background x-ray flux is at the class C2 level.

At midnight there were 6 spotted regions on the visible disk. Solar flare activity was high. A total of 3 C, 1 M and 2 X class events was recorded during the day. Optically uncorrelated flares: C4.4 at 19:54, C5.4 at 20:37 and C3.1 at 22:36 UTC.

Region 10486 decayed slowly as it began to rotate over the southwest limb. Flares: M3.9 at 15:32 UTC.
Region 10487 decayed slowly and quietly.
Region 10488 decayed in the trailing spot section and rotated partly out of view at the northwest limb. Further X class flares are possible today and tomorrow while the region is at and just behind the limb. Flares: X2.7/2B at 01:30 and X3.9/2F at 09:55 UTC.
Region 10495 decayed slowly and quietly.

Spotted regions not numbered by NOAA/SEC:
[S297] A new region emerged in the northeast quadrant on November 3. Location at midnight: N12E07.
[S298] A new region emerged in the northeast quadrant on November 3 just west of region S297. Location at midnight: N13E01.

Comment added at 06:48 UTC on November 4: A fairly strong solar wind shock was observed at SOHO at 05:53 UTC when solar wind speed increased abruptly from 512 to 700 km/sec. The interplanetary magnetic field has initially been northwards.

Comment added at 09:16 UTC: The interplanetary magnetic field has swung strongly southwards and we can expect major to severe geomagnetic storming during the next 6-12 hours.

Comment added at 13:14 UTC: The planetary A index reached 119 for the 09-12h UTC interval. Since 10h UTC the interplanetary magnetic field has been solidly northwards, this has caused a significant decrease in the geomagnetic disturbance level.

Region 10486 at the southwest limb has been brightening the last hour and a slow increase in the background xray flux has been noted. Perhaps the region is preparing for another large flare?

Coronal mass ejections (CMEs)

November 3: No partially or fully Earth directed CMEs observed.

November 2: A fast and large full halo CME was observed after the X8 flare in region 10486. The CME could reach Earth early on November 4.

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 small coronal hole (CH65) in the northern hemisphere could rotate into a geoeffective position on November 5-6.

Processed SOHO/EIT 284 image at 01:06 UTC on November 4. 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 quiet to unsettled early on November 4. During the first half of the day a CME impact is expected and this could cause active to major geomagnetic storm conditions for the remainder of the day. Quiet to unsettled is likely on November 6-7 with a few unsettled to active intervals possible on November 7-8 due to a high speed stream from coronal hole CH65.

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 16 33 S17W75 1430 FKC gamma-delta
10487 2003.10.25 6 5 N12W48 0040 CSO classification was CAO
at midnight
10488 2003.10.27 9 10 N08W82 1250 FKC beta-gamma-delta
10489 2003.10.27     S12W89     plage
10490 2003.10.27     S12W66     plage
10491 2003.10.27     S08W84     plage
10494 2003.10.30     S23W44     plage
10495 2003.10.30 5 8 S22W35 0110 DSO  
10496 2003.10.31     S12W30     plage
S294 emerged on
2003.10.29
    S09W20     plage
S296 emerged on
2003.11.01
    S07E00     plage
S297 emerged on
2003.11.03
  1 N12E07 0000 AXX  
S298 emerged on
2003.11.03
  2 N13E01 0000 BXO  
Total spot count: 36 59
SSN: 76 119

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 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)
2003.11 189.2 (1) 17.0 (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.


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