Solar Terrestrial Activity Report

Last major update issued on March 9, 2004 at 04:40 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update March 2, 2004)]
[Historical solar and geomagnetic data charts 1954-2003 (last update January 16, 2004)]
[Archived reports (last update March 3, 2004)]

Recent activity

The geomagnetic field was quiet to unsettled on March 8. Solar wind speed ranged between 327 and 383 km/sec.

Solar flux measured at 20h UTC on 2.8 GHz was 107.8. The planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 7.3).
Three hour interval K indices: 11222321 (planetary), 11313321 (Boulder).

The background x-ray flux is at the class B2 level.

At midnight there were 4 spotted regions on the visible disk. Solar flare activity was low. Only 1 C class event was recorded during the day. 

Region 10569 was quiet and stable.
Region 10570 was mostly unchanged with polarity intermixing observed at several locations both in the leading and trailing spot sections. A minor M class flare is possible.

Spotted regions not numbered by NOAA/SEC:
[S368] This region emerged on March 8 in the southwest quadrant. Location at midnight: S04W64.
[S369] A new region emerged on a coronal island inside coronal hole CH84 on March 8.  Location at midnight: S15E13.

Coronal mass ejections (CMEs)

March 6-8: No partly or fully earth directed 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 large recurrent trans equatorial coronal hole (CH84) will be in a geoeffective position on March 7-11. CH84 developed on March 7-8, particularly in the southeastern and central parts. An extension of CH84, or possibly a new coronal hole, developed in the southwest quadrant.

Processed SOHO/EIT 284 image at 01:06 UTC on March 9. The darkest areas on the solar disk are likely coronal holes.

Forecast

The geomagnetic field is expected to be quiet to minor storm on March 9 and unsettled to major storm on March 10-14 due to a high speed stream from coronal hole CH84.

Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor (propagation was fair to good at 02h UTC but deteriorated quickly). Propagation along long distance north-south paths is poor. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Vibración (Venezuela). Quite a few east coast North American stations were noted at 02h UTC, most of those stations were not audible two hours later].

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. When the high speed stream has arrived the color changes to green.
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 NOAA/SEC. 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. SEC active region numbers in the table below and in the active region map above are the historic SEC/USAF numbers.

Active region Date numbered SEC
spot
count
STAR
spot
count
Location at midnight Area Classification Comment
10567 2004.02.27 4   S14W79 0030 BXO rotated out of view
10569 2004.03.04 2 2 S12W26 0020 HSX  
10570 2004.03.05 19 26 S14E46 0750 FKO beta-gamma
S367 emerged on
2004.03.06
    S13W13     plage
S368 emerged on
2004.03.08
  4 S04W64 0020 CRO  
S369 emerged on
2004.03.08
  2 S15E13 0010 BXO  
Total spot count: 25 34
SSN: 55 74

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)
2003.02 124.5 46.0 78.3 (-2.5)
2003.03 131.4 61.1 74.0 (-4.3)
2003.04 126.4 60.0 70.1 (-3.9)
2003.05 115.7 55.2 67.6 (-2.5)
2003.06 129.3 77.4 65.0 (-2.6)
2003.07 127.7 83.3 61.8 (-3.2)
2003.08 122.1 72.7 60.0 (-1.8)
2003.09 112.2 48.7 (58.9 predicted, -1.1)
2003.10 151.7 65.5 (56.2 predicted, -2.7)
2003.11 140.8 67.3 (53.5 predicted, -2.7)
2003.12 114.9 46.5 (50.9 predicted, -2.6)
2004.01 114.1 37.2 (46.7 predicted, -4.2)
2004.02 107.0 46.0 (42.1 predicted, -4.6)
2004.03 101.7 (1) 14.0 (2) (39.7 predicted, -2.4)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2) Unofficial, accumulated value based on the Boulder (NOAA/SEC) sunspot number. The official international sunspot number is typically 30-50% less.

This report has been prepared by Jan Alvestad. It is based partly on my own observations and analysis, and partly on data from some of these solar data sources. All time references are to the UTC day. Comments and suggestions are always welcome.


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