Sporadic E layer

Fundamental information of sporadic E layer (Es) came many years ago (in the 1970’s of the last century). Topical Critical frequency (and MUF) is possible to obtain from near Ionospheric Observation (via Internet). The height of Es is about 100 km over the Earth surface.

There are two fundametal theories about Es. First (briefly): Interaction of the magnetic field of the Earth and so called Shear winds on 110 km high and ionized athoms of former meteority dust (it’s my nonprofessional opinion). Second (briefly): Intertaction of a temperary edge of metheorology cyclone and a high temperature storm. It generats so called Shock waves. These waves atteck ionosfere E layer. This layer generates “clodes” of Es.

Es season starts at the end of May and ends at the begginig of September every year. Smaller Es comes at the beggining of January.

Es can be used from high Short Waves (24.9 and 28 MHz bands). The “charmed” 50 MHz band is the most interested one for me. From time to time it could be possible to operate on 144 MHz band with DX stations (up to QRB let’s say 3000 km).