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Date: Fri, 03 Mar 2000 12:36:28
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: Flares and conditions
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At 09:47 3/03/00 -0000, G3XDV wrote:
>Not sure how much influence the flares had on the conditions (it's 
>easy to see coincidence as evidence), especially as the good 
>conditions Larry experienced last month coincided with a very high 
>A index (50+), a few days =after= the major flares. The A index 
>was 18 on the 1st, and is reported today (from yesterday's data) as 
>down to 12. Nevertheless this is interesting data.

Solar activity (storms -flares) have immediate effects on propagation (as
shortwave blackout or MDE) that are caused by electromagnetic radiation and
delayed effects (as aurora on VHF) that are caused by ionised particles
travelling at much slower speed. The delay can be several days. The fact
that the improved propagation noted by Larry correlates with the A-index
could mean the it are these delayed effects that affect LF propagation.

73, Rik