Last major update issued on March 9, 2005 at 04:25 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 minor storm on March 8. Solar wind speed ranged between 622 and 845 km/sec under the influence of a high speed stream from CH149.
Solar flux measured at 20h UTC on 2.8 GHz was 93.5. The planetary
index was 26 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 45533334 (planetary), 45433334 (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 very low. No C class events were recorded during the day.
Region 10741 lost the trailing spots, however, several small spots emerged in the leading spot section.
Region 10742 added spots and penumbral area. The region has a significant amount of polarity intermixing and further growth will increase the chances of minor M class flares occurring.
Spotted regions not numbered by NOAA/SEC:
[S523] This region emerged near the southwest limb on March 7 and somewhat to the southwest of the position of spotless region 10739. SEC and USAF chose to reuse the old region number. Location at midnight: S07W79.
March 6-8: 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 13:06 UTC on March 8. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on March 9 and 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 weak signal. The only North American stations noted were CJYQ 930 with a fair signal and WWZN 1510 kHz with a weak signal.
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||3||S07W81||0040||AXX||spotless, this is new region S523. Actual location: S03W81|
classification was DAI at midnight, area 0110
|Total spot count:||22||27|
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||81.2 (1)||6.4 (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.