Tim
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Solar Terrestrial Activity Report
http://www.dxlc.com/solar/
Recent activity [November 26, 2004 at 04:40 UTC]
The geomagnetic field was quiet to minor storm on November 25. Solar wind speed ranged between 455 and 556 km/sec under the influence of a high speed
stream from coronal hole CH128.
Solar flux measured at 20h UTC on 2.8 GHz was 109.4. The planetary A index was 20 (STAR Ap - based on the mean of three hour interval ap indices: 20.1).
Three hour interval K indices: 45344322 (planetary), 44333423 (Boulder).
The background x-ray flux is at the class B2 level.
At midnight there were 3 spotted regions on the visible solar disk. The solar flare activity level was low. A total of 1 C class event was recorded during the day. That
flare was a C2.6 event at 11:01 with an origin behind the northeast limb.
Region 10704 decayed slowly and quietly.
Region 10706 developed slowly as a few spots emerged in the south and southwest.
Region 10707 became less complex as the positive polarity spot in the north separated from the negative polarity spots in the main penumbra.
Coronal mass ejections (CMEs)
November 23-25: No obviously Earth directed CMEs observed.
Coronal holes
Recurrent coronal hole CH128 in the southern hemisphere was in a geoeffective position on November 21-23. Large and well defined recurrent trans equatorial
coronal hole CH129 will rotate into a geoeffective position on November 27-28.
Forecast
The geomagnetic field is expected to quiet to active on November 26 and quiet to unsettled on November 27-29. Unsettled to major storm is possible on
November 30 when the high speed stream from coronal hole CH129 arrives.
The is 60-100% probability that effects from a coronal hole could reach Earth within the next 5 days.
Propagation (radio wave)
Long distance low and medium frequency (below 2 MHz) propagation along east-west paths over high and upper middle latitudes is poor to very poor. Propagation
along long distance north-south paths is poor.
Report by Jan Alvestad/DXLC: http://www.dxlc.com
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'So much to learn, so little time!'
DreamScape - http://dreamscape.0catch.com/dreamscape.htm
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