Last major update issued on March 16, 2005 at 02:35 UTC.
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The geomagnetic field was quiet on March 15. Solar wind speed ranged between 349 and 429 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 108.2. The planetary
A
index was 4 (STAR Ap - based on the mean of three hour interval ap
indices: 4.1).
Three hour interval K indices: 21111111 (planetary), 21112112 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there were 4 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 1 C class event was recorded during the day.
Region 10741 rotated out of view at the northwest limb. Flare: C2.0 at 06:47 UTC.
Region 10742 decayed further, particularly in the trailing spot section.
Region 10743 was quiet and stable.
Spotted regions not numbered by NOAA/SEC:
[S524] This region redeveloped spots on March 14. Slow decay was observed on March 15 and the region could soon become
spotless. Location at midnight: N16W01.
[S525] A new region emerged in the southeast quadrant on March 14 and had a single small spot late on March 15. Location at midnight:
S13E20.
March 13-15: No obvious 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 coronal hole (CH152) in the northern hemisphere was probably in a geoeffective position on March 14. This coronal hole appears to have decayed somewhat over the last rotation.
Processed SOHO/EIT 284 image at 13:06 UTC on March 11. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be mostly quiet on March 16. Quiet to active conditions are possible on March 17-18 due to effects from CH152.
| 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.
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to occasionally fair. Propagation along long distance north-south paths is poor. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela) with a fair signal, at times WWNN Boca Raton FL was noted as well. On other frequencies the best signals were noted from VOCM on 590, WFTL West Palm Beach FL on 850, CJYQ on 930 and KNR (Greenland) on 650 kHz.
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 |
|---|---|---|---|---|---|---|---|
| 10741 | 2005.03.04 | 3 | N10W80 | 0100 | DSO | rotated out of view | |
| 10742 | 2005.03.07 | 20 | 15 | S05W24 | 0330 | EKO | classification was EAO at midnight, area 0220 |
| 10743 | 2005.03.09 | 5 | 7 | S08W04 | 0290 | HKX | classification was CHO at midnight, area 0260 |
| S524 | visible on 2005.03.10 |
2 | N16W01 | 0000 | AXX | ||
| S525 | emerged on 2005.03.14 |
1 | S13E20 | 0000 | AXX | ||
| Total spot count: | 28 | 25 | |||||
| SSN: | 58 | 65 | |||||
| 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) |
| 2004.01 | 114.1 | 37.3 | 52.0 (-2.8) |
| 2004.02 | 107.0 | 45.8 | 49.3 (-2.7) |
| 2004.03 | 112.0 | 49.1 | 47.1 (-2.2) |
| 2004.04 | 101.2 | 39.3 | 45.5 (-1.6) |
| 2004.05 | 99.8 | 41.5 | 43.9 (-1.6) |
| 2004.06 | 97.4 | 43.2 | 41.7 (-2.2) |
| 2004.07 | 119.1 | 51.0 | 40.3 (-1.4) |
| 2004.08 | 109.6 | 40.9 | 39.2 (-1.1) |
| 2004.09 | 103.1 | 27.7 | (37.4 predicted, -1.8) |
| 2004.10 | 105.9 | 48.4 | (35.2 predicted, -2.2) |
| 2004.11 | 113.2 | 43.7 | (33.3 predicted, -1.9) |
| 2004.12 | 94.5 | 17.9 | (31.0 predicted, -2.3) |
| 2005.01 | 102.2 | 31.3 | (28.3 predicted, -2.7) |
| 2005.02 | 97.2 | 29.1 | (25.9 predicted, -2.4) |
| 2005.03 | 93.3 (1) | 21.1 (2) | (24.1 predicted, -1.8) |
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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