Last major update issued on January 9, 2005 at 04:25 UTC.
[Solar and 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 2, 2005)]
The geomagnetic field was quiet to major storm on January 8. Solar wind speed ranged between 445 and 666 km/sec. The interplanetary magnetic field was mostly northwards, the only intervals where the IMF was significantly southward was at the beginning of the day and around 07:30 UTC.
Solar flux measured at 20h UTC on 2.8 GHz was 88.5. The planetary A
index was 30 (STAR Ap - based on the mean of three hour interval ap indices: 29.5).
Three hour interval K indices: 66343322 (planetary), 45343322 (Boulder).
The background x-ray flux is at the class A8 level.
At midnight there was 1 spotted region on the visible solar disk. The solar flare activity level was low. A single C class event was recorded during the day.Region 10718 rotated fully into view. The region has mixed polarities and further C class events are possible. Flare: C1.0 at 19:57 UTC.
January 6-8: No obvious fully or partly Earth directed CMEs were observed.
Coronal hole 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 small, recurrent coronal hole in the southern hemisphere was likely in a geoeffective position on January 6-7. The associated high speed stream could become geoeffective on January 9 or 10.
Processed SOHO/EIT 284 image at 01:06 UTC on January 8. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to unsettled on January 9-10 with a possibility of a few active intervals due to weak coronal hole effects. Mostly quiet conditions are likely on January 11-12.
|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 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). On other frequencies the only signal from North America was WWZN on 1510 (very weak). During local sunrise on January 8 Greenland was noted on 570 and 650 kHz and KBRW Barrow AK could be heard on 680 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|
spotless for the
second consecutive day
classification was EAO
at midnight, area 0140
not a separate region,
part of 10718
|Total spot count:||4||7|
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||90.6 (1)||8.4 (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.