Solar Terrestrial Activity Report

Last update January 14, 2003 at 03:10 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update 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 13, 2003)]

Recent activity

The geomagnetic field was quiet to unsettled on January 13. Solar wind speed ranged between 361 and 412 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 171.8. The planetary A index was 8 (STAR Ap - based on the mean of three hour interval ap indices: 9.4).
Three hour interval K indices: 32123322 (planetary), 32112322 (Boulder).

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

At midnight there were 8 spotted regions on the visible disk, 2 of which have not yet been numbered. Solar flare activity was low. A total of 8 C class events were recorded during the day. Spotless region 10244 was the source of a C1.4 flare at 01:25, a C1.2 flare at 03:57 and a C4.2 flare at 16:15 UTC. A C2.4 event at 13:05 UTC appears to have been associated with an erupting prominence (image courtesy SOHO/EIT team) at the northeast limb.

Region 10242 rotated out of view at the southwest limb. Flares: C1.0 at 06:37, C3.1 at 14:11 and a C2.2 long duration event peaking at 22:40 UTC.
Region 10247 decayed slowly and quietly.
Region 10249 decayed further and will likely become spotless today.
Region 10250 was quiet and generally unchanged.
Region 10251 added some trailing spots and some small spots north of the large leading penumbra. An M class flare is possible.
Region 10254 was mostly unchanged and quiet.

Region 10255 was split off from region 10251 on January 12 by SEC/NOAA. There are not yet any convincing arguments as to why this split was necessary.
Region 10256 was split off from region 10254 on January 12 by SEC/NOAA. Regions 10254 and 10256 make up one bipolar region with the negative polarity area in the west and the main positive area to the east. It remains to be seen if SEC will merge the "two" regions again.

New region 10257 emerged quickly in the northeast quadrant.

Spotted regions not yet numbered by SEC/NOAA:
[S73] A new region emerged in the southwest quadrant before noon on January 13. The region is already decaying and could become spotless early on January 14.
[S74] A new region rotated into view at the northeast limb before noon on January 13. Quite a bit of activity has been observed at the northeast limb but I'm not yet sure if this activity has its origin in the trailing spots of this region or if there is another region about to rotate into view. Flare: C1.5 at 04:36 UTC.

Coronal mass ejections (CMEs)

January 11-13: 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 obvious coronal holes are currently approaching geoeffective positions.

Processed SOHO EIT 284 image at 19:06 UTC on January 13. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on January 14-18. 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 4   S07W87 0120 DAO rotated out of view
10244 2003.01.03     S22W84     plage
10245 2003.01.03     N12W59      
10246 2003.01.06   N09W80     plage
10247 2003.01.06 37 36 S16W21 0150 EAI  
10249 2003.01.07 1 1 S15W62 0020 HRX  
10250 2003.01.07 4 9 S26E00 0130 CAO  
10251 2003.01.07 16 37 S14E06
(SEC:
S14E09)
0080 CAO beta-gamma
classification was FKO
at midnight, area 0280,
region 10255 included
10252 2003.01.09     S03E05     plage
10253 2003.01.10 5   N11W77
(SEC:
N09W73)
0020 CRO actually spotless
location corrected,
SEC spots are in
region S72
10254 2003.01.10 2 4 S15E37
(SEC:
S14E29)
0100 HAX location corrected,
classification was ESO
at midnight, area 0170
STAR spot count
includes region 10256
10255 2003.01.12 9   S13E01 0200 CKO split off from region
10251
10256 2003.01.12 1   S17E41 0070 HSX split off from region
10254. At midnight the
area in question had
only positive polarity
spots.
10257 2003.01.13 3 8 N16E23 0010 BXO classification was DAO
at midnight, area 0040
S72 emerged on
2003.01.10
    N07W72     now spotless
S73 emerged on
2003.01.13
  1 S21W30 0000 AXX  
S74 visible on
2003.01.13
  6 N06E70 0050 CAO  
Total spot count: 82 102
SSN: 182 182

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)
2003.01 158.7 (1) 66.7 (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.


[DX-Listeners' Club]