Last major update issued on December 4, 2003 at 05:00 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 1, 2003)]
The geomagnetic field was quiet to slightly unsettled on December 3. Solar wind speed ranged between 343 and 434 km/sec.
Solar flux measured at 20h UTC on 2.8 GHz was 123.8. The planetary A
index was 7 (STAR Ap - based on the mean of three hour interval ap indices: 8.1).
Three hour interval K indices: 22222322 (planetary), 11112211 (Boulder).
The background x-ray flux is at the class B4 level.
At midnight there were 8 spotted regions on the visible disk. Solar flare activity was low. A total of 4 C class events were recorded during the day.
Region 10508 behind the southwest limb was fairly active. Flares: C1.6 at 06:35, C1.0 at
10:33, C2.3 at 20:07 and C1.8 at 20:34 UTC.
Region 10509 decayed slowly and quietly.
Region 10510 developed several new spots.
Region 10513 was quiet and stable.
Region 10515 decayed quickly and could soon become spotless.
Region 10516 decayed and was quiet.
Region 10517 added a few small spots and was quiet.
New region 10518 emerged in the southeast quadrant on November 30 and was numbered by SEC 3 days later. The region decayed slowly on December 3 and could soon become spotless.
Spotted regions not numbered by NOAA/SEC:
[S319] This region emerged in the southeast quadrant between regions 10515 and 10516 on December 3. Location at midnight: S08E08.
December 2: A full halo CME was observed in LASCO C3 images beginning at 11:18 UTC. This CME was large and very wide. While expansion was fast off of the west limb, the CME was faint and slow over the east limb. A flank CME impact is possible on December 5 or 6.
December 1 and 3: No partly or fully earth directed CMEs 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 recurrent trans equatorial coronal hole (CH70) was in a geoeffective position on December 1 - December 2. CH70 appeared to be decaying on December 3. A large recurrent trans equatorial coronal hole (CH71)will be in a geoeffective position on December 5-11 with the associated high speed stream influencing the geomagnetic field from December 7 or 8.
Processed SOHO/EIT 284 image at 19:05 UTC on December 3. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet early on December 4. A high speed stream from coronal hole CH70 is likely to cause unsettled to minor storm conditions later in the day and on December 5. A weak CME impact is possible on December 5 and could result in unsettled to active conditions. A strong high speed stream from coronal hole CH71 should dominate the solar wind from December 7 or 8 until approximately December 15.
Long distance low 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 good to occasionally very good. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay with a strong to very strong signal. Impressive signals were observed from several stations from Brazil, e.g. Rádio Bandeirantes (Rio de Janeiro) on 1360 and Rádio Clube Paranaense on 1430 kHz while weaker signals were noted on 1230, 1240 and 1570 kHz to mention a few].
|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 HRX
classification was CAO
at midnight, area 0040
classification was BXO
at midnight, area 0020
classification was CAO
classification was DAO
formerly region S318
classification was BXO
|Total spot count:||30||48|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.06||129.3||77.4||(65.3 predicted, -2.5)|
|2003.07||127.7||85.0||(61.9 predicted, -3.4)|
|2003.08||122.1||72.7||(59.0 predicted, -2.9)|
|2003.09||112.2||48.8||(57.0 predicted, -2.0)|
|2003.10||151.7||65.6||(54.3 predicted, -2.7)|
|2003.11||140.8||67.2||(51.6 predicted, -2.7)|
|2003.12||135.5 (1)||12.2 (2)||(49.0 predicted, -2.6)|
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.