Last major update issued on November 21, 2004 at 04:50 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update November 4, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update November 4, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update November 4, 2004)]
[Historical solar and geomagnetic data charts 1954-2004 (last update November 8, 2004)]
[Archived reports (last update November 20, 2004)]
The geomagnetic field was unsettled to active on November 20. Solar wind speed ranged between 407 and 511 km/sec, mainly under the influence of a high speed stream from coronal hole CH127. A new disturbance arrived just before 17h UTC at ACE. Solar wind speed increased from 460 to 550 km/sec. Solar wind speed increased from 430 to 500 km/sec at SOHO and from 460 to 550 km/sec at ACE in about half an hour. ACE EPAM data indicates an increase in proton levels at this time and for the remainder of the day. The signature of this disturbance is unusual and there is no obvious origin. A possible reverse solar wind shock was observed at SOHO at 00:59 UTC on November 21. This was associated with a sudden increase in solar wind speed from 490 to 600 km/sec, a sudden decrease in solar wind density and a quick decrease in the total field of the interplanetary magnetic field.
Solar flux measured at 20h UTC on 2.8 GHz was 99.3. The planetary A
index was 18 (STAR Ap - based on the mean of three hour interval ap indices: 18.5).
Three hour interval K indices: 34344333 (planetary), 34343333 (Boulder).
The background x-ray flux is at the class B1 level.
At midnight there were 2 spotted regions on the visible solar disk. The solar flare activity level was very low. No C class events was recorded during the day.Region 10701 decayed slowly and quietly.
November 18-20: No obviously 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
Recurrent coronal hole CH128 in the southern hemisphere will rotate into a geoeffective position on November 21-23.
Processed SOHO/EIT 284 image at 01:06 UTC on November 21. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on November 21 and quiet to unsettled on November 22-23.
|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 Cristal del Uruguay. Two weak unidentified Brazilians were noted as well. The only North American station heard was WWZN 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|
area was 0040
classification was DSO
at midnight, area 0080
|Total spot count:||10||7|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2004.05||99.8||41.5||(42.8 predicted, -2.7)|
|2004.06||97.4||43.2||(40.0 predicted, -2.8)|
|2004.07||119.1||51.0||(38.2 predicted, -1.8)|
|2004.08||109.6||40.9||(36.6 predicted, -1.6)|
|2004.09||103.1||27.7||(34.7 predicted, -1.9)|
|2004.10||105.9||48.4||(32.5 predicted, -2.2)|
|2004.11||115.5 (1)||53.6 (2)||(31.0 predicted, -1.5)|
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.