Solar Terrestrial Activity Report

Last update November 10, 2002 at 03:30 UTC. Minor update posted at 17:20 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 2, 2002)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 2, 2002)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update November 2, 2002)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)]
[Archived reports (last update November 9, 2002)]

Recent activity

The geomagnetic field was quiet to unsettled on November 9. Solar wind speed ranged between 348 and 410 km/sec. A solar wind shock was observed at ACE at 18:00 UTC with a sudden increase in solar wind speed from 360 to 400 km/sec. This shock probably had its origin in an unexpected CME but was unusual in that ACE EPAM parameters did not indicate the presence of a CME and that there was a gradual increase in solar wind density during the hours prior to the arrival of the shock.

Solar flare activity was moderate. Solar flux was 190.6, the planetary A index was 9 (STAR Ap - based on the mean of three hour ap indices: 10.0).
Three hour interval K indices: 22122333 (planetary), 11111133 (Boulder).

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

A proton event and an associated polar cap absorption event is in progress. The above 10 MeV proton flux has so far peaked near the 240 pfu level.

At midnight there were 9 spotted regions on the visible disk. A total of 14 C and 1 M class events were recorded during the day. A C4.7 flare at 09:54 UTC apparently had an origin just behind the northwest limb. Several flares have been observed early on Nov.10: C5.4 at 01:24, C5.5 at 01:33, C6.2 at 02:02, C7.7 at 02:14, C8.1 at 02:17 and a long duration M2.4 event peaking at 03:21 UTC. Activity has been observed in regions 10180 and 10191.

Region 10176 was quiet and stable.
Region 10177 decayed quietly with most of the decay occurring in the southern spot section.
Region 10180 decayed further in the trailing spot section and lost quite a few of the intermediate spots as well. A magnetic delta structure is still present in the leading penumbra as well as in the largest intermediate penumbra. There is still a chance of a major flare. Flares: C1.5 at 00:38, C2.8 long duration event peaking at 02:31, C1.6 at 04:26, C6.3 at 11:58, M4.6/2B (associated with moderate type II and IV sweeps and having its origin in the southeastern part of the region) proton flare at 13:23 and C4.1 at 15:26 UTC.
Region 10182 was quiet and stable.
Region 10185 developed slowly and quietly.
Region 10188 decayed moderately quickly and was mostly quiet.
Region 10189 was mostly unchanged and quiet.
Region 10190 was generally unchanged and quiet.
Region 10191 developed slowly and appears to have a magnetic delta structure in the easternmost penumbra. M class flares are possible. Flare: C7.9 at 17:52 UTC.

Comment added at 17:20 UTC on November 10: The M2 event early today in region 10180 was associated with a type II sweep and a fairly fast CME mainly off the southwest limb. Region 10180 has since decayed significantly and the most active areas have been behind the northwest limb and in region 10191. Region 10191 has developed quickly and is already much larger than region 10180. There is at least one magnetic delta structure in this region and a major flare is possible. The geomagnetic field has been quiet to minor storm. A coronal stream is beginning to dominate the solar wind and solar wind speed has been increasing slowly since 13h UTC.

Coronal mass ejections (CMEs)

November 7-8: No obviously geoeffective CMEs were observed.

November 9: A full halo CME was observed after the M4 event in region 10180. The CME was well defined over the southern hemisphere limbs and fairly weak over the north pole and the northern part of the northeast limb. The CME will likely impact Earth sometime between 18h UTC on November 11 and noon on November 12 and could cause unsettled to minor geomagnetic storm conditions.

Coronal holes

The southernmost extension of the northern polar coronal hole was in a geoeffective position on November 7. A trans equatorial coronal hole will likely be in a geoeffective position on November 12-13.

Enhanced SOHO EIT 284 image at 19:06 UTC on November 9. The black areas on the solar disk  are coronal holes.

Forecast

The geomagnetic field is expected to be unsettled to minor storm on November 10-12. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor.

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)

The above image is a test composite image displaying the currently spotted regions overlaid by a coronal hole image. The basis for the region image is a SOHO/MDI image from late on November 9. Region numbering and other image processing has been applied by myself. 

Data for all numbered solar regions according to the Solar Region Summary provided by SEC/NOAA. Comments are my own, as is the STAR spot count (spots observed at or just prior to 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
10174 2002.10.29     S26W86     plage
10176 2002.10.29 1 1 N10W68 0250 HSX  area was approx.
0140 at midnight
10177 2002.10.30 5 5 N18W63 0160 DAO  
10179 2002.11.01     S01W34     plage
10180 2002.11.01 38 31 S10W41 0630 FKC beta-gamma-delta
10181 2002.11.02     S07W47     plage
10182 2002.11.02 1 1 S18W24 0060 HSX  
10184 2002.11.03     S05W28     plage
10185 2002.11.03 12 23 S13W02 0160 CAO classification should
be DAO
10186 2002.11.05     N20W50     plage
10187 2002.11.06     N08W31     plage
10188 2002.11.06 8 7 N10W19 0090 DAO  
10189 2002.11.06 4 4 N12E21 0030 DSO  
10190 2002.11.07 4 3 S22E28 0040 DAO  
10191 2002.11.08 11 22 S17E63 0310 EAI beta-gamma-delta?
S20 emerged on
2002.10.31
    N15W79     plage
S25 emerged on
2002.11.05
    N15W33     plage
S29 emerged on
2002.11.08
  N15E12     plage
Total spot count: 84 97
SSN: 174 187

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
2001.10 207.6 125.5 114.0 (-0.1)
2001.11 210.6 106.5 115.5 (+1.5)
2001.12 235.1 132.2 114.6 (-0.9)
2002.01 226.6 114.1 113.5 (-1.1)
2002.02 205.0 107.4 114.7 (+1.2)
2002.03 179.5 98.4 113.4 (-1.3)
2002.04 189.8 120.7 110.5 (-2.9)
2002.05 178.4 120.8 (108.2 predicted, -2.3)
2002.06 148.7 88.3 (104.5 predicted, -3.7)
2002.07 173.5 99.9 (99.6 predicted, -4.9)
2002.08 183.6 116.4 (95.6 predicted, -4.0)
2002.09 175.8 109.3 (91.8 predicted, -3.8)
2002.10 167.0 97.5 (87.7 predicted, -4.1)
2002.11 178.9 (1) 60.6 (2) (82.4 predicted, -5.3)

1) Running average based on the daily 20:00 UT observed solar flux value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (SEC/NOAA) sunspot number. The official international sunspot number is typically 25-45% less.

This report has been prepared by Jan Alvestad. It is based partly on my own observations and interpretations, and partly on data from sources noted in solar links. Comments and suggestions are always welcome.


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