Hi Jay thanks for the confirmation.....:-))
Also the VLF effects, I have never been quite sure of the effects down
there.....but they should be similar. I wonder whether the beacons will throw
up any data about the 500kHz effects over long distances??
Alan
--- On Fri, 9/3/12, [email protected] <[email protected]> wrote:
> From: [email protected] <[email protected]>
> Subject: Re: LF: Big solar flare - major geomagnetic storms to follow
> To: [email protected]
> Date: Friday, 9 March, 2012, 12:42
> Alan
>
> Thanks for the update and insight.
>
> Absolutely no trace of Stefan's signal in CT last night. A
> few nights back he was 25+ dB s/n (in 28 mHz). Long distance
> VLF signal levels below normal as well.
>
> Jay W1VD WD2XNS WE2XGR/2
>
>
> ----- Original Message ----- From: "ALAN MELIA" <[email protected]>
> To: <[email protected]>
> Sent: Friday, March 09, 2012 5:57 AM
> Subject: Re: LF: Big solar flare - major geomagnetic storms
> to follow
>
>
> Hi all more geomag storming this morning. It looks as though
> I might have got my timing wrong. However the 56 hours to
> the Kp=7 event is a bit slow for such a big event, and the
> predicted speed of that CME.
>
> I suspect this mornings event may be what I refered to
> yesterday as a "sub-storm". This occurs when the plasma
> cloud sweeps past Earth and some is then trapped in a
> "magnetic bottle" in the tail of the magnetosphere. The
> magnetic field becomes highly distorted and twisted by the
> extra hot charge. Just as in the Sun-spots this strain is
> relieved as the field snaps back into a lower energy state.
> The excess energy which is released as the field collapses
> is transfered to the plasma "glob". The result is that two
> parts of the plasma are fired off at very high speed. one
> towads Earth and one away from Earth (to conserve
> momentum....a basic law of physics). This mornings event was
> the shock of that plasma "bullet" arriving. I believe this
> mornings event may have been of this nature.
>
> How does it affect LF? The charge from the "bullet" is
> injected into the ring current so tops up the charge
> reservoir, and this lengthens the period of excess
> attenuation in the night-time D-layer. There is some
> discrepancy between the Dst estimates. The Colorado estimate
> is running at about -50nT whilst the Kyoto value is around
> -150nT. Kyoto is based on a number of ground located
> magnetometer observations and is prone to rather wild
> fluctuations, and often "overshoots". The Colorado plot is
> based on a calculation using the solar wind parameters as
> observed by the ACE satellite. From my experience I find the
> latter to be more useful/meaningful in terms of LF effects.
>
> Overall I think this indicates a mild effect. Long distance
> night-time paths will be affected for a week or so. For a
> good indication of the progress of of the recovery, watch
> the Dst as it returns to around -20nT....the indication of
> quiet, good propagation conditions. Just before the
> conditions settle there can be some exceptionally good
> nights, probably caused by favourable fading/multipath.
> These are very location dependent and do not work for
> everyone.
>
> However keep watching..... NOAA predict the possibility of
> more X-Class flares from the current spots, with the
> associated CMEs.
>
> Good LF DXing !!
>
> Alan
> G3NYK
>
>
>
>
>
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