Last major update issued on January 22,
2005 at 05:05 UTC.
geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update January 2, 2005)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 2, 2005)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update January 2, 2005)]
[Historical solar and geomagnetic data charts 1954-2004 (last update November 8, 2004)]
[Archived reports (last update January 19, 2005)]
The geomagnetic field was quiet to very severe storm on January 20. Solar wind speed ranged between 551 and 1004 km/sec. A very strong solar wind shock was observed at SOHO at 16:48 UTC with a sudden increase in wind speed from 570 to near 950 km/sec. This was the arrival of the CME associated with the X7 proton flare on January 20.
Solar flux measured at 20h UTC on 2.8 GHz was 113.8. The planetary
index was 61 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 31322886 (planetary), 32322775 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 4 spotted regions on the visible solar disk. The solar flare activity level was moderate. A total of 9 C and 2 M class events was recorded during the day. Region 10718 behind the southwest limb became significantly more active and was the source of the following flares: C1.3 at 08:35, C1.7 at 09:12, C1.3 at 12:12 and M1.2 at 13:55 UTC.Region 10720 rotated partly out of view at the northwest limb. The region remains complex and another major proton flare is possible while the region is at and just behind the limb. Flares: C5.8 at 00:24, C6.3 at 04:27, C1.6 at 06:36, C1.8 at 06:46, M1.7 at 10:16, C1.6 at 17:11 and C1.6 at 20:49 UTC.
January 21: No obvious fully or partly Earth directed CMEs
January 20: A full halo CME was observed after the X7 event in region 10720 at 07h UTC.
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 (CH140) in the northern hemisphere was in a geoeffective position on January 18-20. The associated high speed stream will likely become geoeffective on January 22.
Processed SOHO/EIT 284 image at 21:58 UTC on January 21. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on January 22 due to CME effects and quiet to active on
January 23-24 due to a high speed stream from coronal hole CH140.
|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
east-west paths over high and upper middle latitudes is useless.
Propagation along long distance north-south paths is very poor.
Atlantic propagation conditions are normally monitored every night on
1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Vibración (Venezuela), both heard only occasionally and
with very weak signals. On other frequencies only a few stations from Brazil were weakly audible 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|
formerly region S502
classification was DAI at midnight, area 0120
|10726||2005.01.21||3||2||S02E27||0040||CSO|| formerly region S501
classification was DSO at midnight, area 0020
|Total spot count:||29||21|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2004.07||119.1||51.0||(39.6 predicted, -1.9)|
|2004.08||109.6||40.9||(38.0 predicted, -1.6)|
|2004.09||103.1||27.7||(36.1 predicted, -1.9)|
|2004.10||105.9||48.4||(33.9 predicted, -2.2)|
|2004.11||113.2||43.7||(32.0 predicted, -1.9)|
|2004.12||94.5||17.9||(29.7 predicted, -2.3)|
|2005.01||107.8 (1)||37.6 (2)||(27.0 predicted, -2.7)|
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.