Last major update issued on March 28, 2006 at 04:40 UTC.
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(last update March 2, 2006)]
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[Historical solar and
geomagnetic data charts 1954-2005 (last update March 3, 2006)]
[Archived reports (last update
March 2, 2006)]
The geomagnetic field was quiet to unsettled on March 26. Solar wind speed ranged between 331 and 414 (all day average 365) km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 74.3. The planetary A index
was 9 (STAR Ap - based on the mean of three hour interval ap
indices: 8.8).
Three hour interval K indices: 33001223 (planetary), 33102213 (Boulder).
The background x-ray flux is at the class A6 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was very low. No C class events were recorded during the day.
Spotted regions not numbered by NOAA/SEC:
[S636] This region rotated into view at the southeast limb on March
27. There is little separation between the opposite polarity areas and further
development is possible. Location at midnight: S12E73.
March 25-27: No partly or fully Earth directed CMEs were observed in LASCO imagery.
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
No significant coronal holes are currently in or near Earth facing positions.
Processed SOHO/EIT 284 image at 01:06 UTC on March 28. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on March 28-31.
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 poor. Propagation on long distance northeast-southwest paths is poor to very poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela) with a poor signal. From North America the most common east coast stations were audible again with the best signals from 930 CJYQ, 1130 WBBR and 1510 WWZN.
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 |
---|---|---|---|---|---|---|---|
S636 | 2006.03.27 | 3 | S12E73 | 0010 | BXO | ||
Total spot count: | 0 | 3 | |||||
SSN: | 0 | 13 |
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 | 74.4 (1) | 17.5 (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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