Solar Terrestrial Activity Report

Last update December 1, 2002 at 01:55 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 30. Solar wind speed ranged between 466 and 562 km/sec under the influence of a coronal stream.

Solar flare activity was low. Solar flux was 146.2, the planetary A index was 16 (STAR Ap - based on the mean of three hour ap indices: 16.3).
Three hour interval K indices: 34433333 (planetary), 24433322 (Boulder).

The background x-ray flux is at the class B4 level.

At midnight there were 6 spotted regions on the visible disk. Only 1 C class event was recorded during the day.

Region 10202 decayed into spotless plage.
Region 10204 decayed slowly and could become spotless today.
Region 10205 was quiet and stable.
Region 10207 was again mostly unchanged in penumbral area. The region continued to expand longitudinally and the main positive and negative polarity areas are now well separated.
Region 10208 developed slowly and was quiet.
New region 10209 rotated into view at the southeast limb on Nov.29 and was numbered on Nov.30. Flare: C1.1 at 22:12 UTC.
New region 10210 emerged near the southwest limb on Nov.29 and was numbered on Nov.30.

Coronal mass ejections (CMEs)

November 28-30: No obviously geoeffective CMEs noted.

Coronal holes

Coronal hole history (starting late October 2002)

A weakening recurrent trans equatorial coronal hole was in a geoeffective position on November 27-28.

Processed SOHO EIT 284 image at 19:06 UTC on November 30. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to active on December 1-2 under the influence of a coronal stream and quiet to unsettled on December 3-4. 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
10200 2002.11.20 1   S03W67 0000 AXX spotless all day
10202 2002.11.24 7   N15W16 0010 BXO now spotless
10203 2002.11.26 1   N09E17 0000 AXX spotless all day
10204 2002.11.27 7 2 N20W02 0010 BXO classification was AXX
at midnight, area
was 0000 then
10205 2002.11.27 1 1 N19E23 0020 HSX area was 0040 at
midnight
10206 2002.11.27   S27E04     plage
10207 2002.11.27 19 15 S19E31 0290 EAI area near 0370 at
midnight
10208 2002.11.29 12 18 N10E63 0210 DAO  
10209 2002.11.30 8 11 S20E62 0140 DAO formerly region S38
10210 2002.11.30 4 5 S09W77 0060 DSO formerly region S38
Total spot count: 60 52
SSN: 150 112

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)
2002.11 168.7 (1) 160.9 (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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