Non reciprocal conditions from ZL

By   2 June 2021 05:54

With the development of the new solar cycle, conditions are changing. This is nothing new of course, but a distinct effect was found, that is really puzzling.

Compared to last year, signals from Europe to New Zealand are not much different, but SNR reports of ZL stations are considerably weaker now.

Using Proplab Pro, ray tracing was tried. Current solar terrestrial values were applied and it seems that rays from ZL to EU run in a sort of chordal hop mode (reflecting from the F layer and go in a straight line over the E layer to the next reflection from the F layer).

Rays will propagate fine, with hardly any absorption, but returning to the ground is more difficult when compared with the situation of last year. The tilt angle in the F layer around sunrise in Europe is insufficient to provide an exit mechanism for these shallow rays.

The EU to ZL path runs through the E-F valley with steeper angles and does escape from the duct near New Zealand.

More research will be done, hoping to shed more light on this phenomenon.

Whatever its cause, it is disappointing for the 60 metres fans and the worst case scenario is to have to wait until the next solar minimum. The good news is that not all is bad during a solar minimum. A bit like the weather, every season has its good points.