Dear Watchers and Listeners,
Further to my post about conditions on 20 March at 1100z at Jeff's qth and
SIMILAR OBSERVED ABNORMAL CONDITIONS in the southern hemisphere:
I have had a chance to gather together some of the available
solar/terrestial data and the SOHO satellite data.
This is what has occurred.
(1) From SOHO (reference www.umtof.umd.edu/pm) the Proton Monitor indicated
that the Proton fluence had been dropping from 11 March to its lowest point
at 0000z on 20/3. The solar wind came off a low point of 300km/hr @ 0000z
20/3 to a high point of 600 km/hr @ 0000z 22/3.
(2) From Terrestial Observations the Electron Fluence >2MeV dipped to its
lowest point @ 2300z 20/3 then rapidly increased to 22/3.
(3) An M class flare from region #8183 occurred @ 0117 - 0127 - 0134z on 19/3.
(4) No other significant flares until 22/3.
The above information is consistent with my previous statement about
"hollowness of expectedness".
The ionosphere reacts to the flare immediately on the daylight side of the
earth.
0130z (19/3) places the effect squarely over the Pacific.
34 hours later (1100z 20/3) the slower moving protons and electrons begin
arriving in the vicinity of the earth (and SOHO) and we begin to see the
effects on the earth's magnetic field (and hence the ionosphere).
The residue of the solar UV burst from the flare (whilst not a particularly
large flare: M1.8) is still affecting the ionosphere in the vicinity of the
equatorial areas of the Pacific.
Jeff receives two paths of signal.
(1) the normal short path which is slightly down on normal, only just
beginning to be affected by auroral effects and
(2) the enhanced signal path from the south/west central Pacific not
normally available at sunrise time.
(If you have read my previous post you will note that signals up as far as
24 mhz were coming in from the same northern region of the ionosphere from
UA0 to VK3).
WHILST NOT A "PERFECT" EXPLANATION, THE EVIDENCE FROM SOLAR/TERRESTIAL
OBSERVATION IS UNEQUIVOCAL. AT PERIODS OF LOWISH SUN ACTIVITY LIKE THE
PRESENT, YOU CAN OBSERVE THE INDIVIDUAL FLARE EFFECTS MUCH BETTER THAN IN
PERIODS OF HIGH ACTIVITY WHERE THE HIGHER BACKGROUND MASKS THE INDIVIDUAL
EFFECTS.
Any comments? Glad to answer and provide web site references for those
interested in finding out more.
Cheers
Peter VK3QI
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