Solar Terrestrial Activity Report

Last update January 10, 2003 at 04:25 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update January 1, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 1, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update January 1, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update October 13, 2002)]
[Archived reports (last update January 6, 2003)]

Recent activity

The geomagnetic field was quiet to unsettled on January 9. Solar wind speed ranged between 277 and 339 km/sec. A weak coronal stream began to dominate the solar wind after 17h UTC and solar wind speed has gradually increased since then.

Solar flux measured at 20h UTC on 2.8 GHz was 182.9. The planetary A index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 7.9).
Three hour interval K indices: 22112333 (planetary), 11112222 (Boulder).

The background x-ray flux is at the class B8 level.

At midnight there were 9 spotted regions on the visible disk, 1 of which has not yet been numbered. Solar flare activity was moderate. A total of 14 C and 1 M class events were recorded during the day.

Region 10242 decayed losing penumbral area in all sections. The region may still be capable of producing an M class flare. Flares: C2.3 at 00:39, C9.8/1F at 01:39 and C2.0 at 22:37 UTC.
Region 10244 decayed further and could become spotless late today or tomorrow.
Region 10245 decayed significantly and is quickly heading towards spotlessness.
Region 10247 developed quickly, particularly in the trailing spot section. A major flare is possible. Flares: C3.4 at 02:53 and C1.6 at 08:49 UTC.
Region 10249 decayed losing both spots and penumbral area.
Region 10250 added a few small spots and was otherwise mostly unchanged. A minor M class flare is possible.
Region 10251 did not change much and still has a magnetic delta structure in the trailing spot section. Further M class flares are likely. Flares: C2.4 at 00:31, M1.0/1N at 05:37, C2.6 at 07:52, C2.5 at 13:23, C2.4 at 17:26, C1.7 at 18:23 and C4.3 at 18:50 UTC.
New region 10252 emerged near the southeast limb.

Spotted regions not yet numbered by SEC/NOAA:
[S71] A new region is rotating into view at the southeast limb. Location at midnight: S15E84.

Coronal mass ejections (CMEs)

January 7-9: No obviously geoeffective CMEs observed.

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

No coronal holes are currently approaching geoeffective positions.

Processed SOHO EIT 284 image at 01:06 UTC on January 10. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to active on January 10 and quiet to unsettled on January 11-12. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is fair.

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. Compare to the previous day's image.

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 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
10242 2003.01.02 35 28 S08W34 0310 DAI beta-gamma
10244 2003.01.03 7 4 S22W31 0030 CSO  
10245 2003.01.03 6 3 N12W05 0030 CAO classification was HRX
at midnight, area 0020
10246 2003.01.06   N09W28     plage
10247 2003.01.06 36 46 S17E34 0340 DAI classification was EAI
at midnight, area 0550
10248 2003.01.07 1   S10W69 0050 AXX now spotless, area was
0020 at most early in
the day
10249 2003.01.07 13 9 S15W08 0040 DSO  
10250 2003.01.07 5 9 S27E53 0160 CAO classification was DAO
at midnight
10251 2003.01.07 12 15 S13E58 0330 EAO beta-gamma-delta
10252 2003.01.09 1 1 S04E61 0010 AXX  
S68 emerged on
2003.01.04
  N02W20     plage
S69 emerged on
2003.01.05
  N13W51     plage
S71 visible on
2003.01.09
  3 S15E84 0100 CSO
Total spot count: 116 118
SSN: 206 208

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)
2002.01 226.6 114.1 113.5 (-1.1)
2002.02 205.0 107.4 114.6 (+1.2)
2002.03 179.5 98.4 113.3 (-1.3)
2002.04 189.8 120.7 110.5 (-2.9)
2002.05 178.4 120.8 108.8 (-1.7)
2002.06 148.7 88.3 106.2 (-2.6)
2002.07 173.5 99.6 (102.1 predicted, -4.1)
2002.08 183.6 116.4 (98.5 predicted, -3.6)
2002.09 175.8 109.6 (95.5 predicted, -3.0)
2002.10 167.0 97.5 (92.0 predicted, -3.5)
2002.11 168.7 95.0 (86.7 predicted, -5.3)
2002.12 157.2 81.6 (82.4 predicted, -4.3)
2003.01 149.3 (1) 39.3 (2) (79.4 predicted, -3.0)

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. All time references are to the UTC day. Comments and suggestions are always welcome.


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