Last major update issued on March 20, 2005 at 04:00 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 16, 2005)]
The geomagnetic field was quiet to minor storm on March 19. Solar wind speed ranged between 364 and 539 km/sec under the influence of a mostly low speed stream from CH152.
Solar flux measured at 20h UTC on 2.8 GHz was 93.0. The planetary
index was 14 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 54222111 (planetary), 54322211 (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 total of 2 C class events was recorded during the day.
Region 10742 rotated out of view at the southwest limb early in the day. Flare: C2.2 at
Region 10743 lost a few small spots and was otherwise mostly unchanged. Flare: C2.3 at 07:07 UTC.
Spotted regions not numbered by NOAA/SEC:
[S526] This region emerged quickly on March 19 in the southeast quadrant. C flares are possible. Location at midnight: S13E13.
March 17-19: 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 rotate to a geoeffective position on March 21-23, the westernmost part is only in the northern hemisphere and poorly defined.
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 20-23 becoming quiet to unsettled on March 24 due to effects from CH153. Quiet to active conditions are likely on March 25-26 as the coronal hole effects increase.
|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 and improving. 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. Propagation towards North America was somewhat improved over the last day with more stations audible. The best signal was a strong KNR (Greenland) on 650 kHz; CJYQ 930, WBZ 1030 and WBBR 1130 all had fair signals at times.
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||1||S06W93||0250||HKX||rotated out of view|
|10743||2005.03.09||20||10||S08W57||0390||DKI||classification was DKO at midnight, area 0300|
|Total spot count:||21||21|
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||94.5 (1)||26.2 (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.