Last major update issued on January 2, 2004 at 05:10 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update December 2, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update December 2, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update December 2, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update December 30, 2003)]
The geomagnetic field was unsettled to minor storm on January 1. Solar wind speed ranged between 526 and 597 km/sec under the influence of a high speed stream from coronal hole CH73.
Solar flux measured at 20h UTC on 2.8 GHz was 116.0. The planetary A
index was 27 (STAR Ap - based on the mean of three hour interval ap indices: 27.9).
Three hour interval K indices: 34555433 (planetary), 34455443 (Boulder).
The background x-ray flux is at the class B5 level.
At midnight there were 3 spotted regions on the visible disk. Solar flare activity was low. A total of 14 C class events were recorded during the day. Region 10528 behind the west limb produced a C6.4 flare at 03:21 UTC.
Region 10534 developed moderately quickly. Should the region develop further, minor M class flares will become
possible. Flares: C2.1 at 02:32, C2.5 at 05:40, C1.8 at 10:26, C1.0 at 12:04 UTC.
New region 10535 emerged in the southwest quadrant.
New region 10536 rotated into view at the southeast limb. This is a fairly large region capable of producing M class flares. Flares: C2.7 at 01:12, C4.0 at 01:33, C3.7 at 01:46, C1.3 at 05:01, C8.0 at 06:54, C1.8 at 08:55, C1.2 at 19:12, C3.1 at 22:43 and C2.0 at 23:38 UTC.
December 31 - January 1: No partly or fully earth directed CMEs observed from the limited data set currently available.
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 (CH73) was in a geoeffective position on December 28-29. A large, recurrent trans equatorial coronal hole (CH74) will probably be in a geoeffective position January 1-7.
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 quiet to active on January 2 under the diminishing influence of a high speed stream from coronal hole CH73. Quiet to unsettled is likely on January 3 with unsettled to major storm expected January 4-7 as a high speed stream from coronal hole CH74 dominates the solar wind.
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 station tonight: Radio Cristal del Uruguay with occasional interference from Radio Rafaela (Argentina)].
|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 DAI
at midnight, area 0170
classification was CSO
at midnight, area 0070
classification was DKO
at midnight, area 0750
|Total spot count:||17||26|
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||116.0 (1)||1.5 (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.