Last major update issued on March 4, 2006 at 05:25 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, 2006)]
[Solar cycles 1-20]
[Graphical comparison
of cycles 21, 22 and 23 (last update March 2, 2006)]
[Graphical
comparison of cycles 2, 10, 13, 17, 20 and 23 (last update March 2, 2006)]
[Historical solar and
geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update
March 2, 2006)]
The geomagnetic field was inactive to quiet on March 3. Solar wind speed ranged between 368 and 458 (all day average 412) km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 75.5. The planetary A index
was 4 (STAR Ap - based on the mean of three hour interval ap
indices: 3.6).
Three hour interval K indices: 10011221 (planetary), 10012201 (Boulder).
The background x-ray flux is below the class A1 level.
At midnight the visible solar disk was spotless (consecutive spotless days: 4). The solar flare activity level was very low. No C class events were recorded during the day.
March 1-3: No obviously fully or partly Earth directed CMEs were 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 trans equatorial coronal hole (CH215) appears to have become larger over the last solar rotation and could be in an Earth facing position on March 6-8.
Processed SOHO/EIT 284 image at 01:20 UTC on February 28. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet on March 4-8 while a high speed stream from CH215 could cause ocassionally unsettled to active conditions on March 9-12.
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) Effects from a CME are likely to be observed at 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.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is fair. Propagation on long distance northeast-southwest paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: WLAM Lewiston ME. Propagation was best to Cuba with excellent signals noted from several stations (890 Radio Progreso and 930 Radio Surco a.o). Quite a few North American east coast stations were audible at fair to good signal levels.
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 |
---|---|---|---|---|---|---|---|
10856 | 2006.02.27 | 0 | 0 | S09E15 | plage | ||
Total spot count: | 0 | 0 | |||||
SSN: | 0 | 0 |
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) |
2005.01 | 102.2 | 31.3 | 34.6 (-0.6) |
2005.02 | 97.2 | 29.2 | 33.9 (-0.7) |
2005.03 | 89.9 | 24.5 | 33.5 (-0.4) |
2005.04 | 86.0 | 24.2 | 31.6 (-1.9) |
2005.05 | 99.3 | 42.7 | 28.9 (-2.7) |
2005.06 | 93.7 | 39.3 | 28.8 (-0.1) |
2005.07 | 96.4 | 40.1 | 29.1 (+0.3) |
2005.08 | 90.5 | 36.4 | 27.4 (-1.7) |
2005.09 | 91.1 | 21.9 | (25.6 predicted, -1.8) |
2005.10 | 77.0 | 8.5 | (23.8 predicted, -1.8) |
2005.11 | 86.3 | 18.0 | (21.4 predicted, -2.4) |
2005.12 | 90.7 | 41.2 | (18.5 predicted, -2.9) |
2006.01 | 83.4 | 15.4 | (15.4 predicted, -3.1) |
2006.02 | 76.5 | 4.7 | (12.3 predicted, -3.1) |
2006.03 | 76.2 (1) | 0.0 (2) | (10.1 predicted, -2.2) |
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% lower.
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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