Solar Terrestrial Activity Report

Last update November 28, 2002 at 04:10 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 24, 2002)]

Recent activity

The geomagnetic field was unsettled to active on November 27. Solar wind speed ranged between 459 and 640 km/sec.

Solar flare activity was low. Solar flux was 142.6, the planetary A index was 21 (STAR Ap - based on the mean of three hour ap indices: 23.0).
Three hour interval K indices: 44444333 (planetary), 34433133 (Boulder).

The background x-ray flux is at the class B7 level.

At midnight there were 8 spotted regions on the visible disk. A total of 12 C class events were recorded during the day.

Region 10198 developed further in the trailing spot section and could produce a minor M class flare while rotating over the southwest limb today. Flares: C2.4 at 01:19, C6.7 long duration event peaking at 02:51, C2.3 at 09:43, C1.8 at 14:28, C3.8 at 16:53, C2.9 at 22:24 and C1.9 at 23:07 UTC.
Region 10200 added a couple of small spots and was otherwise unchanged and quiet.
Region 10202 gained several trailing spots as the region developed slowly.
Region 10203 was quiet and stable.
New region 10204 emerged in the northeast quadrant and initially developed quickly. Slow decay was observed during the latter half of the day as the region lost most of the spots that had emerged early on.
New region 10205 rotated into view at the northeast limb on Nov.26 and was numbered on Nov.27.
New region 10206 emerged in the southeast quadrant early in the day with several spots. The region decayed after noon and could soon become spotless.
New region 10207 rotated partly into view on Nov.26 and was numbered on Nov.27. The region could be capable of producing occasional minor M class flares. Flare: C3.5 at 21:32 UTC.

Coronal mass ejections (CMEs)

November 25-27: No obviously geoeffective CMEs noted.

Coronal holes

A trans equatorial coronal hole will rotate into a geoeffective position on November 27-28.

Processed SOHO EIT 284 image at 19:06 UTC on November 27. The black areas on the solar disk are coronal holes.

Forecast

The geomagnetic field is expected to be quiet to active on November 28-29. A coronal stream could reach Earth on Nov.30 and cause unsettled to minor storm conditions. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor to 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)

Composite image based on a SOHO/MDI continuum image and overlaid by a coronal hole image. Region numbering has been included.

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
10198 2002.11.15 6 8 S18W75 0370 FKO beta-gamma
10199 2002.11.20     N28W80      
10200 2002.11.20 3 3 S03W22 0020 CSO classification was CRO
at midnight
10202 2002.11.24 7 11 N13E27 0030 CSO classification was CRO
at midnight
10203 2002.11.26 2 2 N09E56 0020 CSO single polarity spots,
classification was HSX
at midnight 
10204 2002.11.27 8 6 N16E40 0040 DSO area was 0020 at
midnight, classification
was CRO then.
10205 2002.11.27 1 1 N19E63 0050 HSX formerly region S36
10206 2002.11.27 1 1 S26E44 0010 HSX classification was AXX
at midnight
10207 2002.11.27 4 4 S19E69 0220 DAO formerly region S37,
area was near 0400
at midnight
Total spot count: 32 36
SSN: 112 116

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 (109.0 predicted, -1-5)
2002.06 148.7 88.3 (107.0 predicted, -2.0)
2002.07 173.5 99.9 (103.6 predicted, -3.4)
2002.08 183.6 116.4 (100.2 predicted, -3.4)
2002.09 175.8 109.3 (96.4 predicted, -4.8)
2002.10 167.0 97.5 (92.3 predicted, -4.1)
2002.11 171.6 (1) 148.2 (2) (87.0 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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