Hi Roelof, I have in the past discussed these odd polar paths with Laurence.
One though is a 'location filter' consider a path where the transition
through the auroral belt happens to coincide with a ground reflection??
Though I think we are due a wipeout for a couple of days. The Dst has just
gone to zero nT prior to a dip expected from the Kp=5 this morning. Another
effect I have seen is what I refer to as 'leakage' I am not sure about this
but there is data that shows poor signals after a long geomagmetically qiet
period. Though the E-layer is theoretically ionised by non-solar effects
(cosmic rays) there is obviously some effect. The interesting point is this
poor prop period can be ended by a low-level geomagmetic event (Kp=4) so it
is possible that nighttime ionisation levels in the E layer benefit from
mild geomagnetic activity. We may see more of this as we go into this Solar
Minimum. these things remain fascinating.
Best Wishes
Alan G3NYK
----- Original Message -----
From: "Roelof Bakker" <[email protected]>
To: <[email protected]>
Sent: Sunday, December 17, 2017 10:39 AM
Subject: Re: LF: Re: A robust session on 630-meters : K9FD (/KH6) -> LA2XPA
and more...
Hello Rik,
T/A propagtion from lower latitude NDB's is very poor at the moment,
whilst reception from Nunavut is excellent.
There was even a short opening around 10:00 UTC from Churchill at
the other side of the Hudson Bay. This almost happens every year in
December / January. However, I have never seen the difference
between reception from lower Canada and up north as large as it is
now.
My guess is that a different propagation mode is at work.
If anyone has more information, it will be much appreciated.
Though trans-polar propagation in Winter is common from northern
Europe at my latitude (52 N) this is much more rare. Yet, lately I
could receive 3 NDB's from Alaska here.
73,
Roelof Bakker, pa0rdt
|
