E layer openings

We are familiar with the spring and summer Es (sporadic E) openings, especially on bands like 10m and 6m. These are usually about 1500km. Occasionally multi-hop openings occur. Some of the long distance contacts may be multi-hop. 

However, I have long suspected that some very long paths are due to some other form of E layer propagation. Every June 6m opens up to Japan, which is a very long way. This regular propagation seems to be linked with mesospheric clouds that seem to form at this time of year. 

EI7GL reports on his blog that there have been at least 2 openings from Australia to Europe on 6m this spring. The probability of this being multi-hop Es seems extremely low. My theory (totally unproved) is this is due to some sort of chordal hop E layer propagation. This could also account for some of the transatlantic openings.

We have a lot to learn about E layer propagation. This is one reason 6m is called the "magic band".

See https://ei7gl.blogspot.com/p/50-mhz.html .

Es (sporadic E) super DX

OK, I may be wrong, but to me multi-hop (lots of hops) Es does not seem to fit with some of the "real DX" being worked on 10m and 6m.

Some of the paths being worked would need 5-6 hops or more. To me, it seems far more probable these very long paths depend on some sort of chordal hop between patches of E layer ionisation without the intermediate hops. Of course, multi-hops are possible in some cases, but I am sure these are the exceptions. For European DX on 10m and 6m I am sure 1 and 2 hop Es is likely in the summer months.

Es to northern Europe

In an earlier post I mentioned that more northerly stations seemed to be more predominant later in the Es season. This is based on nothing scientific, but 6m FT8 RX results today are predominantly from northern Europe.

If this observation is true I have absolutely no idea why. Regarding E layer propagation, I am sure there is a lot still to learn, especially regarding "real DX", by which I mean really long distances outside Europe such as to Japan, the Caribbean or North America. 

In my view multi-hop Es does not fit these "real DX" cases. I may be wrong.