Every year about now, 6m opens from Japan to western Europe. For a long time I have been of the view that this is E layer propagation, but not sporadic-E (Es). This is a very long way and it seems to be linked with noctilucent cloud formation.
Southgate News reports on a Space weather piece about extremely cold temperatures in the mesosphere. Noctilucent clouds are forming at lower latitudes.
See
http://www.southgatearc.org/news/2020/june/record-cold-in-the-mesosphere.htm#.XuD6RIjYrrcot
I have also got views on some of the other long paths worked on 6m such as the UK to the USA and the UK to South America. I am again convinced this is
some sort of E layer propagation, but think it is very
unlikely to be Es. OK, some openings could be Es, but the chance of this being multiple hop Es seems
very unlikely. Maybe in 20 years' time we will know. In the meantime we have fun!
I also wonder if the Japanese path would also work on microwaves. Maybe one year some suitably equipped 23cm or even 3cm stations could have a try. Quite some firsts! Imagine if some EME equipped stations had a go.
See
https://sites.google.com/site/g3xbmqrp3/vuhf/noctilucent