Last major update issued on January 3, 2005 at 03:40 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 unsettled to minor storm on January 2. Solar wind speed ranged between 539 and 975 km/sec. An unusually high speed stream from coronal hole CH136 arrived at SOHO just after 02h UTC.
Solar flux measured at 20h UTC on 2.8 GHz was 100.0. The planetary A
index was 33 (STAR Ap - based on the mean of three hour interval ap indices: 33.3).
Three hour interval K indices: 44543535 (planetary), 44533535 (Boulder).
The background x-ray flux is at the class B1-B2 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 1 C and class event was recorded during the day.Region 10715 decayed significantly in the northeastern part. There is still little separation between the positive and negative polarity areas near the southeastern edge of the main penumbra. An M class flare is possible. Flare: C1.2 at 13:06 UTC.
January 1: A large and partially Earth directed CME is likely to have been associated with the X1.7 event early in the
day and could reach Earth during the first half of January 3.
December 31 and January 2: No obviously 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
Recurrent large trans equatorial coronal hole CH136 was in a geoeffective position on December 31-January 2.
Processed SOHO/EIT 284 image at 01:06 UTC on January 3. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to minor storm on January 3-5 due to a CME and coronal hole effects.
|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 to poor. Propagation along long distance north-south paths is poor to fair. Trans Atlantic propagation conditions are normally monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay (presumed). On other frequencies propagation was best towards Brazil. Only two stations from North America were noted: CBA Moncton on 1070 and WWZN Boston on 1510 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|
classification was DAI
classification was BXO
at midnight, area 0020
|10717||2004.12.31||3||N08W86||0110||DSO||rotated out of view|
|Total spot count:||22||22|
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||99.5 (1)||3.3 (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.