Re: LF: 477.7 kHz CW

["Alan Melia" <alan.melia@btinternet.com>]

Hi Roelof, this current event is a very different kind of event to the usual CME or Solar hole high-speed flow. There does not seem to be any "dense" stream of plasma, but the Solar wind velocity has incresed from 300km/sec to 600km/sec......but it seems there are not a lot of ions/electrons around. The Kyoto Dst plunged (based on earth bound magnetometers) but the Colorado estimate based on Ace Solar wind data hardly changed  (thought the data may not be reliable at present) Also the plunge to -75nT shown on Kyoto was followed by a steep rise (recovery in less than 24 hours which is quite unusual). I am thinking this might mean that there was little hot-electron precipitation from this event (normally 6 hours of Kp=6 peaking 7 would depress the Dst for 10 days or more.)  You have probably noticed the upward movement of the Dst before the steep fall in normal CME events.....there is no sign of this. I am led to believe that there has been little precipitation of hot electrons into the ionoshere, and it would seem that reports confirm that. I did forget to look at the direction of the IMF.

 

I wonder if the CME style event where there is an upward movement in the Dst (possibly caused by positive ion trapping in the ring current) actually couses electons to be withdrawn from the ionosphere. The literature states that there is a two was exchane of ions and electrons between the ionospher and the ring currents. This "vacuum cleaner" effect prior to the onset of electron precipitation might explain your observation of inproved conditions? 

 

Fascinating stuff :-))

 

Alan

G3NYK

 

----- Original Message -----

From: Roelof Bakker

To: jcraig@mun.ca ; rsgb_lf_group@blacksheep.org

Sent: Saturday, October 29, 2016 11:53 AM

Subject: Re: LF: 477.7 kHz CW

Hello Joe,

Another poor night at least for reception from Canada.

See attachment.

The amazing thing is that I had a proper decode from NAVTEX Bangkok, Thailand on 518 kHz, last evening.

      

20161028 2059 518 $11F HAS Bangkok (Nonthaburi),THA 9325
2016-10-28 20:59:34> ZCZC FR93
2016-10-28 20:59:37> 2016-10-29 8 03:50
2016-10-28 20:59:38>
2016-10-28 20:59:41> FROM BANGKOK RADIO
2016-10-28 20:59:44> (CAT TELEC~~DPUBLIC
2016-10-28 20:59:47> COMPANY LIMITED~)
2016-10-28 20:59:51> ~NOTICE TO MARINERS
2016-10-28 20:59:54> NO.67/2556(TEMM~RARY)
2016-10-28 20:59:57> GU~F ~~ THAILAN
2016-10-28 20:59:59> ND~ILLING ~PJRATIDNS
2016-10-28 20:59:59>

The Kyoto Dst made another dive overnight. I have often noted that before such an event propagation can increase spectacular. Does anyone know of a good explanation of this phenomenon?

Best regards,

Roelof

====================================================================

From: Roelof Bakker, PAoRDT

Location: Middelburg, Zealand SW Netherlands, 51 30 02 N, 03 36 02 E

Locator: JO11tm

Receiver hardware: PERSEUS,

Receiver software: PERSEUS V5

Aerial: pa0rdt-mini-whip, 5 metre up in a hawthorn tree.

====================================================================

 

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