Last major update issued on March 10, 2005 at 05:00 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update March 3, 2005)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update March 3, 2005)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update March 3, 2005)]
[Historical solar and geomagnetic data charts 1954-2004 (last update February 1, 2005)]
[Archived reports (last update March 6, 2005)]
The geomagnetic field was unsettled to active on March 9. Solar wind speed ranged between 593 and 778 km/sec under the influence of a high speed stream from CH149.
Solar flux measured at 20h UTC on 2.8 GHz was 99.9. The planetary
index was 20 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 34433344 (planetary), 34433444 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 2 C class events was recorded during the day. A C1.0 flare at 01:36 UTC had an origin behind the northeast limb.
Region 10741 developed early in the day as negative polarity flux emerged to the southeast of the leader spots. Slow
decay was observed late in the day. Flare: C1.8 at 02:41 UTC.
Region 10742 developed with a significant increase in penumbral area. The magnetic field layout appears to have become simpler over the last day with a significant decrease in polarity intermixing.
New region 10743 rotated into view at the southeast limb.
March 7-9: No obvious fully or partly Earth directed CMEs were observed.
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 coronal hole (CH149) in the northern hemisphere was in a geoeffective position on March 3-7.
Processed SOHO/EIT 284 image at 07:06 UTC on March 9. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on March 10 due to a high speed stream from CH149. Quiet to unsettled is likely on March 11-12.
|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) 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. 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. Before 02:30 UTC both WWNN Boca Raton FL and WLAM Lewiston ME were noted with weak signals. Quite a few stations from the easternmost parts of Canada and the US were heard then, later most North American signals disappeared.
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
|Location at midnight||Area||Classification||Comment|
|10739||2005.02.26||2||S08W92||0090||BXO||strange area and classification, rotated out of view early in the day|
|10741||2005.03.04||17||13||N12E03||0060||DSI||classification was CAI at midnight|
classification was HAX at midnight
|Total spot count:||37||30|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|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||83.2 (1)||8.9 (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.