Solar Terrestrial Activity Report

Last update issued on March 8, 2003 at 04:15 UTC.

[Solar and geomagnetic data - last 4 weeks (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 3, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 3, 2003)]
[Graphical comparison of cycles 10, 13, 17, 20 and 23 (last update March 3, 2003)]
[Historical solar and geomagnetic data charts 1954-2002 (last update January 27, 2003)]
[Archived reports (last update March 3, 2003)]

Recent activity

The geomagnetic field was quiet to active on March 7. Solar wind speed ranged between 420 and 552 km/sec under the influence of a high speed stream from coronal hole CH24 most of the day. This stream appeared to be ending late in the day.

Solar flux measured at 20h UTC on 2.8 GHz was 149.9. The planetary A index was 14 (STAR Ap - based on the mean of three hour interval ap indices: 13.9).
Three hour interval K indices: 33342233 (planetary), 34332232 (Boulder).

The background x-ray flux is at the class B3-B4 level.

At midnight there were 10 spotted regions on the visible disk, 2 of which have not yet been numbered by SEC/NOAA. Solar flare activity was very low.

Region 10295 decayed slowly and quietly and could become spotless today.
Region 10296 decayed slowly and quietly.
Region 10297 decayed slowly and was quiet.
Region 10301 developed slowly in the leader spots while slow decay was observed in the trailing spots.
Region 10302 was quiet and stable.
New region 10303 emerged in the southwest quadrant. The region was decaying late in the day and could soon become spotless.
[New region 10304 was numbered by SEC/NOAA. Unfortunately the spots in this region are the same as those in region 10297. The region should be deleted.]
New region 10305 emerged in the southeast quadrant and has developed moderately quickly. C class flares are possible.
New region 10306 rotated into view at the northeast limb. The region consists of a single, large penumbra.

Spotted regions not yet numbered by SEC/NOAA:
[S120] A new region emerged on March 7 in the southeast quadrant west of region 10305. Location at midnight: S23E10.
[S121] A new region emerged on March 7 in the southern hemisphere near the central meridian. Location at midnight: S20W02.

Coronal mass ejections (CMEs)

March 5-7: 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 recurrent coronal hole (CH25) is rotating into view at the southeast limb and will likely move into a geoeffective position on March 13.

Processed SOHO EIT 284 image at 01:06 UTC on March 8. Any black areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to unsettled on March 8-12. Long distance medium wave (AM) band propagation along east-west paths over high and upper middle latitudes is poor, propagation along north-south paths is fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay, the Radio Rafaela (Argentina) and CPN Radio (Peru) after 02h UTC. On other frequencies North American stations began to appear after 04h UTC.]

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
10293 2003.02.27     S17W76     plage
10294 2003.02.27     S10W67     plage
10295 2003.02.27 3 1 S17W38 0020 CSO classification was HSX
at midnight
10296 2003.02.28 17 23 N13W18 0440 DKO beta-gamma
classification was EKO
at midnight, STAR spot
count includes region
10299
10297 2003.03.01 5 7 S14W12 0030 DSO classification was CSO
at midnight, only
negative polarity spots
10298 2003.03.03     S08W34     plage
10299 2003.03.03 14   N14W08 0030 DSO only negative polarity
spots, these are the
trailing spots of region
10296
10300 2003.03.03 3   N16E14 0010 BXO now spotless
10301 2003.03.04 12 12 N22W05 0050 DAO beta-gamma
10302 2003.03.04 5 1 N20E23 0020 CAO classification was HSX
at midnight
10303 2003.03.07 3 1 S18W47 0010 CSO classification was AXX
at midnight
10304 2003.03.07 12   S13W16 0040 DSO the spots are those
of region 10297,
this region should be
deleted
10305 2003.03.07 6 12 S22E27 0030 DSO classification was DAO
at midnight, area 0060
10306 2003.03.07 1 1 N05E76 0280 HHX  
S115 emerged on
2003.03.02
    S19W47     plage
S116 emerged on
2003.03.02
    N13W69     plage
S117 visible on
2003.03.02
  S25E09     plage
S118 emerged on
2003.03.04
    S26W76     plage
S119 emerged on
2003.03.04
    S15W24     plage
S120 emerged on
2003.03.07
  3 S23E10 0020 CRO  
S121 emerged on
2003.03.07
  1 S20W02 0010 HRX  
Total spot count: 81 62
SSN: 191 162

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)
2002.02 205.0 107.4 114.6 (+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 98.7 (-4.0)
2002.09 175.8 109.6 (94.7 predicted, -4.0)
2002.10 167.0 97.5 (91.2 predicted, -3.5)
2002.11 168.7 95.0 (86.0 predicted, -5.2)
2002.12 157.2 81.6 (81.6 predicted, -4.4)
2003.01 144.0 79.5 (78.6 predicted, -3.0)
2003.02 124.5 46.2 (73.6 predicted, -5.0)
2003.03 145.0 (1) 28.5 (2) (67.9 predicted, -5.7)

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]