Last major update issued on March 5, 2004 at 04:05 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)]
The geomagnetic field was quiet to unsettled on March 4. Solar wind speed ranged between 449 and 601 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 97.5. The planetary A
index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 8.1).
Three hour interval K indices: 22132322 (planetary), 11332222 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 2 spotted regions on the visible disk. Solar flare activity was low. A total of 2 C class events was recorded during the day.
Region 10567 decayed in the leading and trailing spot sections while significant development occurred in the central
section where there is little separation between the opposite polarity areas. Flares: C2.5 at
10:07 and C1.0 at 17:16 UTC.
New region 10569 emerged in the southeast quadrant.
An interesting region at or just behind the southeast limb is brightening and has at least C class flare potential.
March 2-4: No partly or fully earth directed CMEs observed.
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 (CH84) mostly in the northern hemisphere will likely reach a geoeffective position on March 7-8.
Processed SOHO/EIT 284 image at 01:06 UTC on March 5. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on March 5-9.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor. Propagation along long distance north-south paths is fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela) with a strong signal. On other frequencies stations from Venezuela and Puerto Rico had the best signals. A few North American stations were noted as well, mostly from Newfoundland. Propagation towards Florida was excellent during the sunrise opening on March 4 with WPSL on 1590 kHz the best catch].
| Coronal holes (1) | Coronal mass ejections (2) | M and X class flares (3) |
 |
|
 |
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.
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 | 29 | 31 | S12W29 | 0160 | EAC |
beta-gamma classification was EAI at midnight, area 0210 |
| 10568 | 2004.02.28 | S17W84 | plage | ||||
| 10569 | 2004.03.04 | 4 | 7 | S11E34 | 0020 | BXO |
classification was DAO at midnight, area 0050 |
| Total spot count: | 33 | 38 | |||||
| SSN: | 53 | 58 | |||||
| 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 | 97.1 (1) | 6.8 (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 sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.
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