Last update issued on October 16, 2003 at 03:35 UTC.
[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 21-23 (last update October 4, 2003)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update October 4, 2003)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update October 4, 2003)]
[Historical solar and geomagnetic data charts 1954-2003 (last update October 15, 2003)]
[Archived reports (last update October 15, 2003)]
The geomagnetic field was unsettled to severe storm on October 15. Solar wind speed ranged between 583 and 744 km/sec under the influence of a high speed stream from coronal hole CH63.
Solar flux measured at 20h UTC on 2.8 GHz was 95.9. The planetary A
index was 42 (STAR Ap - based on the mean of three hour interval ap indices: 43.8).
Three hour interval K indices: 34764444 (planetary), 34654344 (Boulder).
The background x-ray flux is at the class B3 level.
At midnight there were 2 spotted regions on the visible disk. Solar flare activity was very low.
Region 10477 reemerged quickly with several spots. Both polarities are present within the trailing penumbra. Further
development will likely cause C class flaring and possibly even minor M class flares.
New region 10480 emerged in the northwest quadrant on October 14 and was numbered by SEC the next day. The region has a simple magnetic layout.
October 13-15: No potentially geoeffective 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 hole (CH63) will rotate into a geoeffective position on October 12-17. CH63 has become much smaller over the last rotation, losing most of its extension into the northern hemisphere. CH63 has merged with what was CH59 in the southeast.
Processed SOHO/EIT 284 image at 19:06 UTC on October 15. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be unsettled to minor storm on October 16 and unsettled to active on October 17-21 (possibly with minor storm intervals on October 20) due to a high speed stream from coronal hole CH63.
Long distance low frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is useless. Propagation along north-south paths is poor to fair [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Cristal del Uruguay. Lots of fairly weak signals from stations in Brazil and Argentina noted on other frequencies, i.e. Rádio Jovem Pan in Brasilia on 750 and La Red in Buenos Aires on 910 kHz].
|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.
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.
|Solar region||Date numbered||SEC
|Location at midnight||Area||Classification||Comment|
classification was DAO
at midnight, area 0040
formerly region S277
classification was DAO
at midnight, area 0050
|Total spot count:||9||13|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.04||126.4||60.0||(69.6 predicted, -4.5)|
|2003.05||115.7||55.2||(65.3 predicted, -4.3)|
|2003.06||129.3||77.4||(61.5 predicted, -3.8)|
|2003.07||127.7||85.0||(58.0 predicted, -3.5)|
|2003.08||122.1||72.7||(55.0 predicted, -3.0)|
|2003.09||112.2||48.8||(53.0 predicted, -2.0)|
|2003.10||110.4 (1)||34.5 (2)||(50.3 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 sources noted in solar links. All time references are to the UTC day. Comments and suggestions are always welcome.