CQ Japan on 6m JT65

It is that time of year when 6m opens from Europe to Japan on 6m. This morning I see that Spanish stations are calling JA on 6m JT65. This path opens every year on 6m around this time. The conventional view is this is multi-hop Es. Sorry, but I don't go for this. It may have something to do with E layer ionisation as a result of noctilucent clouds?

See https://sites.google.com/site/g3xbmqrp3/vuhf/noctilucent .