Last major update issued on March 19, 2005 at 06:15 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 16, 2005)]
The geomagnetic field was quiet to unsettled on March 18. Solar wind speed ranged between 353 and 487 km/sec under the influence of a low speed stream from CH152. The coronal hole effects unexpectedly increased during the latter half of the day and early on March 19.
Solar flux measured at 20h UTC on 2.8 GHz was 96.5. The planetary
index was 9 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 11231333 (planetary), 11231333 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was low. A single C class event was recorded during the day.
Region 10742 decayed slowly and rotated to the southwest limb.
Region 10743 was mostly unchanged in the main penumbral area, however, some growth was observed in the southwestermost penumbra. Flare: C1.3 at 02:35 UTC.
March 16-18: 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 recurrent trans equatorial coronal hole (CH153) will likely rotate to a geoeffective position on March 22-23.
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 quiet to minor storm on March 19 and quiet on March 20-21.
|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 very 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. On other frequencies several weak signals from North America were observed near local sunrise, most of them from Newfoundland. CHNC New Carlisle QC on 610 kHz was there too with a very 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|
|10742||2005.03.07||3||3||S06W80||0300||HKX||classification was HAX at midnight, area 0140|
|10743||2005.03.09||14||13||S08W44||0300||DHI||classification was DHO at midnight|
|Total spot count:||17||16|
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||94.6 (1)||24.9 (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.