Andy, There was a passenger on an airliner that took photographs of a very large Aurora at that time. . One of the photographs was shown on TV - ABC World News.
It is likely that the Aurora sparked all these events. I have noticed that there appears to be a link between the start of an aurora and long path 160 meter openings. 73, DX, Bruce-K1FZ On Mon, 6 Feb 2017 14:42:58 +0000, Andy Cook wrote: I think this form of ducting takes place way above the layers of the atmosphere where weather happens. In my experience the magnetospheric ducting is normally localized in impact. If this was really happening in multiple places around the world at the same time on this occasion then I think that is unusual. Andy, G4PIQ -----Original Message----- From: "K1FZ-Bruce" Sent: 06/02/2017 13:46 To: "[email protected]" ; "Topband" Subject: Fwd: Echo on 160m yesterday morning Hi Andy, Ducting takes place over a relatively small area. Depends upon cloud layers and temperature zones This event took place ~ world wide. Band openings between North America to Asia, and Australia. 73 Bruce-k1fz http://www.qsl.net/k1fz/beverage_antenna.html On Mon, 6 Feb 2017 12:20:07 +0000 (GMT), Andy Cook wrote: I think you'll find this was Magnetospheric Ducting. Take a look at some of the articles here http://la3za.blogspot.co.uk/search/label/Unusual%20Propagation and here http://folk.uio.no/sverre/papers/2009_MagnetoDucting-QST-LA3ZA.pdf. Delay depends on your latitude - but couple of hundred millseconds is about right and this is a peak time of year for the effect. I've heard this quite frequently on 80m around mid local-evening during the winter, and one occasion - on 3rd Feb last year - very strongly indeed. That night I was able to hear my echoes with just 25mW into a dipole on 80m - but it's often strong enough to be audible with a few watts. I've read papers which suggested it does also occur on 160m. Reports of these being less strong / gone when you switch to a vertical look plausible as well since they apear to require vertical incidence from the ionosphere. 73, Andy, G4PIQ _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
