Solar Terrestrial Activity ReportSolar Terrestrial Activity Report

Last update December 3, 2002 at 04:00 UTC.
[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update December 2, 2002)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2002)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update December 2, 
2002)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 
2002)]
[Archived reports (last update December 1, 2002)]
Recent activity
The geomagnetic field was quiet to unsettled on December 2. Solar wind speed 
ranged between 447 and 517 km/sec under the weakening influence of a coronal 
stream.
Solar flare activity was low. Solar flux was 146.1, the planetary A index was 11 
(STAR Ap - based on the mean of three hour ap indices: 12.5).
Three hour interval K indices: 23333332 (planetary), 23223323 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 5 spotted regions on the visible disk. A total of 3 C 
class events was recorded during the day.
Region 10205 decayed slowly and quietly.
Region 10207 was mostly unchanged. Flare: C1.8 at 20:33 UTC.
Region 10208 developed slowly early on, then decayed during the latter half of 
the day. A weak magnetic delta is evident in the leading spot section and a 
minor M class flare is possible. Flares: C2.4/1N at 01:56 and C9.5 at 19:27 UTC.
Region 10209 decayed slowly and lost most of its trailing spots.
New region 10211 emerged on December 1, decayed on December 2 and was spotless 
by midnight.
New region 10212 rotated into view at the northeast limb early in the day.
Coronal mass ejections (CMEs)
November 28 - December 2: No obviously geoeffective CMEs noted.
December 2: A bright and large CME was observed in LASCO C2 images beginning at 
18:06 UTC. The CME first appeared off of the northwest limb and became a full 
halo CME in LASCO C3 images. The CME had a backsided origin.
Coronal holes
Coronal hole history (starting late October 2002)
A coronal hole in the northern hemisphere could move into a geoeffective 
position on December 4-5.

Processed SOHO EIT 284 image at 19:06 UTC on December 2. Any black areas on the 
solar disk are likely coronal holes.
Forecast
The geomagnetic field is expected to be quiet to unsettled on December 3-5. Long 
distance medium wave (AM) band propagation along east-west paths over high and 
upper middle latitudes is poor.
      Coronal holes (1)Coronal mass ejections (2)M and X class flares (3)


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 regionDate numberedSEC
      spot
      countSTAR
      spot
      countLocation at midnightAreaClassificationComment
      102022002.11.24 4 N13W400020BXOreemerged briefly,
      spotless at midnight 
      102032002.11.26  N09W09  plage 
      102042002.11.2710 N16W260020BXOreemerged briefly,
      only one spot observed
      during early afternoon,
      spotless at midnight 
      102052002.11.2711N19W030000AXX area was near 0020,
      classification HSX at
      midnight 
      102062002.11.27 S27W22  plage 
      102072002.11.272017S20E060290EAO  
      102082002.11.292226N10E350170DAIbeta-gamma-delta 
      102092002.11.30107S20E350170ESO  
      102112002.12.024S08E040020BXOnow spotless 
      102122002.12.0245N13E750160CAO
      Total spot count:7556
      SSN:155106

Monthly solar cycle data
      MonthAverage solar
      flux at EarthInternational sunspot numberSmoothed sunspot number
      2000.04184.2125.5120.8
      cycle 23 sunspot max. 
      2000.07202.3170.1119.8
      2001.11210.6106.5115.5 (+1.5)
      2001.12235.1132.2114.6 (-0.9)
      2002.01226.6114.1113.5 (-1.1)
      2002.02205.0107.4114.7 (+1.2)
      2002.03179.598.4113.4 (-1.3)
      2002.04189.8120.7110.5 (-2.9)
      2002.05178.4120.8108.8 (-1.7)
      2002.06148.788.3(106.4 predicted, -2.4)
      2002.07173.599.9(102.8 predicted, -3.6)
      2002.08183.6116.4(99.6 predicted, -3.2)
      2002.09175.8109.3(96.6 predicted, -3.0)
      2002.10167.097.5(93.1 predicted, -3.5)
      2002.11168.795.0(87.8 predicted, -5.3)
      2002.12147.9 (1)8.1 (2)(83.5 predicted, -4.3)

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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