We (or at least I) observed this phenom about a four or five weeks ago when AIS was working 400 miles out beyond the G site. Google "Solar Flares & Radio Transmissions" by Richard Gaughan. I was particularly interested in the section on "Reflection". Awaiting the Wacko accusation.
FWIW worth Steve this discussion you may recall was taken up last year as well.I posted on September 8 ,2012.Search IONOSPHERE in the search box above to pick up on the conversation.There is another one I posted which was relating to my real life experience with this as a quartermaster for the USN.