Solar Terrestrial Activity Report

Last update issued on February 15, 2003 at 02:50 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update February 2, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update February 2, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update January 27, 2003)]
[Archived reports (last update February 10, 2003)]

Recent activity

The geomagnetic field was quiet to active on February 14. Solar wind speed ranged between 365 and 563 km/sec under the influence of a coronal stream.

Solar flux measured at 20h UTC on 2.8 GHz was 131.6. The planetary A index was 19 (STAR Ap - based on the mean of three hour interval ap indices: 19.9).
Three hour interval K indices: 43234443 (planetary), 44234432 (Boulder).

The background x-ray flux is at the class B5 level.

At midnight there were 5 spotted regions on the visible disk. Solar flare activity was moderate. A total of 9 C and 1 M class events was recorded during the day. Region 10284 (now behind the northwest limb) produced most of the events: C5.0 at 02:12, C5.2/1F at 05:26, C1.4 at 08:47, M1.2 at 09:18 and C1.2 at 11:47 UTC. Spotless region 10280 at the southwest limb produced a C1.2 flare at 07:11 and a C2.1 flare at 19:28 UTC.

Region 10278 decayed slowly and could become spotless today.
Region 10281 decayed further and is likely to become spotless soon.
Region 10282 developed slowly and could produce further C class flares. Flare: C1.7 at 06:37 UTC.
Region 10285 decayed in the leader spot, however, several small spots emerged.
New region 10287 emerged in the northwest quadrant on February 13 and was numbered one day later. The region has developed moderately quickly and could produce C flares.

Coronal mass ejections (CMEs)

February 12-14: 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

A trans equatorial coronal hole and a southern polar coronal hole extension will rotate into a geoeffective position on February 12-18. 

Processed SOHO EIT 284 image at 01:06 UTC on February 15. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be unsettled to active with occasional minor storm intervals until February 21. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is very poor, propagation along north-south paths is fair to good.

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)

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
10276 2003.02.01 4   S14W90 0100 DAO rotated out of view
10277 2003.02.04 4 S18W60 0020 CRO actually spotless
10278 2003.02.04 5 1 N18W55 0030 CAO classification was AXX
at midnight, area 0010
10280 2003.02.06   S06W81     plage
10281 2003.02.06 1 1 S15W32 0010 HSX  
10282 2003.02.07 7 5 N10W58 0050 DSO classification was DAO
at midnight
10283 2003.02.07 4   N00W39 0020 CSO now spotless
10285 2003.02.08 4 9 S11W01 0030 CAO  
10286 2003.02.09     S13W84     plage
10287 2003.02.14 4 6 N12W50 0020 CRO formerly region S99
classification was DAO
at midnight, area 0060
S90 emerged on
2003.02.04
    S13W58     plage
S98 emerged on
2003.02.13
    N04W55     now spotless
S100 emerged on
2003.02.13
    N11E22     now spotless
Total spot count: 33 22
SSN: 113 72

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 99.6 102.7 (-3.5)
2002.08 183.6 116.4 (99.7 predicted, -3.0)
2002.09 175.8 109.6 (96.7 predicted, -3.0)
2002.10 167.0 97.5 (93.2 predicted, -3.5)
2002.11 168.7 95.0 (88.0 predicted, -5.2)
2002.12 157.2 81.6 (83.6 predicted, -4.4)
2003.01 144.0 79.5 (80.6 predicted, -3.0)
2003.02 135.9 (1) 59.4 (2) (75.5 predicted, -5.1)

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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