Last major update issued on January 5, 2004 at 04:15 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update January 4, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update January 4, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update January 4, 2004)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update January 1, 2004)]
The geomagnetic field was unsettled to active on January 4. Solar wind speed ranged between 556 and 662 km/sec under the influence of a high speed stream from coronal hole CH74.
Solar flux measured at 20h UTC on 2.8 GHz was 119.4. The planetary A
index was 24 (STAR Ap - based on the mean of three hour interval ap indices: 24.1).
Three hour interval K indices: 33444443 (planetary), 33543432 (Boulder).
The background x-ray flux is at the class C1 level.
At midnight there were 3 spotted regions on the visible disk. Solar flare activity was low. A total of 6 C class events was recorded during the day.
Region 10534 decayed slowly and quietly, the leader spots are disappearing.
Region 10535 decayed and lost nearly half of its spots.
Region 10536 was mostly unchanged. An M class flare is possible. Flares: C2.8 at 09:52, C3.5 at 15:26, C3.7 at 15:58, C3.8 at 18:20, C1.5 at 20:35 and C1.9 at 22:37 UTC. This region was the source of the following flares early on January 5: C7.5 at 00:16, C4.9 at 00:57 and a major long duration M6.8 event peaking at 03:46 UTC.
January 2-4: No partly or fully earth directed CMEs observed from the limited data set currently available.
January 5: A fairly large CME (judging from GOES SXI images) was associated with the major M6.8 long duration event in region 10536 early in the day. The CME may have been partly Earth directed.
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 recurrent trans equatorial coronal hole (CH74) was in a geoeffective position January 1-5. This coronal hole has decreased significantly in size over the last rotation, mostly due to the development of region 10534.
Processed SOHO/EIT 284 image at 19:06 UTC on December 26. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on January 5-8 due to a high speed stream from coronal hole CH74. If there was a CME associated with the M6 LDE early on January 5, active to major storm conditions will be possible from late on January 7.
Long distance low 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 fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant stations tonight: Radio Cristal del Uruguay and Radio Rafaela (Argentina) with mostly good, equal strength signals].
|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.
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 CSO
classification was CSO
classification was DKO
|Total spot count:||50||37|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.07||127.7||83.3||(62.0 predicted, -3.0)|
|2003.08||122.1||72.7||(59.4 predicted, -2.6)|
|2003.09||112.2||48.7||(57.5 predicted, -1.9)|
|2003.10||151.7||65.6||(54.7 predicted, -2.8)|
|2003.11||140.8||67.2||(52.0 predicted, -2.7)|
|2003.12||114.9||47.0||(49.4 predicted, -2.6)|
|2004.01||117.0 (1)||7.8 (2)||(45.3 predicted, -4.1)|
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 sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.