Last major update issued on February 14, 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 February 2, 2004)]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22 and 23 (last update February 2, 2004)]
[Graphical comparison of cycles 2, 10, 13, 17, 20 and 23 (last update February 2, 2004)]
[Historical solar and geomagnetic data charts 1954-2003 (last update January 16, 2004)]
[Archived reports (last update February 9, 2004)]
The geomagnetic field was unsettled to active on February 13. Solar wind speed ranged between 568 and 827 km/sec under the influence of a high speed stream from coronal hole CH80.
Solar flux measured at 20h UTC on 2.8 GHz was 107.8. The planetary A
index was 21 (STAR Ap - based on the mean of three hour interval ap indices: 21.5).
Three hour interval K indices: 44444333 (planetary), 45344433 (Boulder).
The background x-ray flux is at the class B1-B2 level.
At midnight there were 5 spotted regions on the visible disk. Solar flare activity was very low. No C class events was recorded during the day.
Region 10554 was mostly unchanged and quiet.
Region 10556 decayed quickly and could soon become spotless.
New region 10557 emerged near the center of the visible disk on February 11 and was numbered two days later by SEC. The region decayed on February 13 and could soon become spotless.
New region 10558 emerged quickly late on February 12 and early on February 13. The positive polarity field had nearly dissipated by the end of the day. The region is decaying and could become spotless today or tomorrow.
Spotted regions not numbered by NOAA/SEC:
[S353] This region emerged in the northwest quadrant on February 13 near coronal hole CH80. Location at midnight: N08W31.
February 11-13: 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 (CH80) was in a geoeffective position on February 9-13.
Processed SOHO/EIT 284 image at 01:06 UTC on February 14. The darkest areas on the solar disk are likely coronal holes.
The geomagnetic field is expected to be quiet to active on February 14-16 due to a high speed stream from coronal hole CH80. Quiet to unsettled is likely on February 17-20.
Long distance low and medium 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 fair. [Trans Atlantic propagation conditions are currently monitored every night on 1470 kHz. Dominant station tonight: Radio Vibración (Venezuela). WWZN Boston on 1510 kHz was noted during most of the listening session].
|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|
rotated out of view
during the last hour
of the day
classification was BXO
at midnight, area 0010
formerly region S351
classification was BXO
at midnight, area 0010
|10558||2004.02.13||2||3||S15E36||0020||CSO||formerly region S352|
|Total spot count:||21||26|
flux at Earth
|International sunspot number||Smoothed sunspot number|
cycle 23 sunspot max.
|2003.08||122.1||72.7||(59.4 predicted, -2.4)|
|2003.09||112.2||48.7||(57.6 predicted, -1.8)|
|2003.10||151.7||65.6||(54.9 predicted, -2.7)|
|2003.11||140.8||67.2||(52.2 predicted, -2.7)|
|2003.12||114.9||47.0||(49.6 predicted, -2.6)|
|2004.01||114.1||37.2||(45.4 predicted, -4.2)|
|2004.02||108.3 (1)||38.3 (2)||(40.8 predicted, -4.6)|
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.