Last major update issued on January 29, 2005 at 05:50 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 unsettled on January 28. Solar wind speed ranged between 343 and 433 km/sec. A fairly low speed stream from coronal hole CH141 arrived at ACE at about 07h UTC. The interplanetary magnetic field was mostly northwards early on, however, stronger southwards fluctuations were observed later in the day.
Solar flux measured at 20h UTC on 2.8 GHz was 84.9. The planetary
index was 6 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 22101132 (planetary), 12011332 (Boulder).
The background x-ray flux is at the class A4 level.
At midnight there were 2 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 10723 was quiet and stable and will soon rotate over the northwest limb.
January 26-28: 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 coronal hole (CH141) in the southern hemisphere was in a geoeffective position on January 25-26. A recurrent coronal hole in the northern hemisphere (CH142) will be in a geoeffective position on January 27-28.
Processed SOHO/EIT 284 image at 19:06 UTC on January 28. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to active on January 29-February 1 due to high speed streams from CH141 and CH142. Occasional minor storm intervals are possible.
|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). Other frequencies had mostly weak signals from North American stations, particularly on frequencies above 1500 kHz.
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|
|10723||2005.01.17||2||1||N05W70||0070||HAX||classification was HSX at midnight, area 0040|
classification was CRO at midnight, area 0020
|10728||2005.01.25||1||S14E24||0010||AXX||spotless for the third consecutive day|
|Total spot count:||13||6|
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||104.0 (1)||48.2 (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.