Last major update issued on January 30, 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 29, 2005)]
The geomagnetic field was quiet to active on January 29. Solar wind speed ranged between 351 and 616 km/sec. The low speed stream from coronal hole CH141 was replaced by a significantly higher speed stream from CH142 near noon.
Solar flux measured at 20h UTC on 2.8 GHz was 86.2. The planetary
index was 20 (STAR Ap - based on the mean of three hour interval ap
Three hour interval K indices: 32343344 (planetary), 23343444 (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 10727 decayed early in the day, then new positive polarity flux emerged very near and to the southwest of the leading negative polarity spots. This may have been a new region emerging in almost the same location as that of 10727, the location of the region is now 2 degrees further south and 3 degrees further to the east than would have been the expected without this new development. The region developed quickly and there may be a weak magnetic delta structure in the leading penumbra.
January 27-29: 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 coronal hole in the northern hemisphere (CH142) was in a geoeffective position on January 27-29.
Processed SOHO/EIT 284 image at 01:06 UTC on January 30. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on January 30-February 1 due to a high speed stream from CH142.
|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). On other frequencies WWZN on 1510 and WDHP on 1620 kHz had the best signals. WDHP actually had a strong 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|
|10723||2005.01.17||2||N06W84||0090||HSX||rotated out of view|
classification was DAO at midnight, area 0110
|Total spot count:||10||17|
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||103.4 (1)||49.2 (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.