The Physical Nature of Sporadic-E

Sporadic-E is different from other forms of ionospheric propagation, regularly supporting long distance contacts well into the VHF range. It's also well-known to be really hard to predict, with signals that are highly unstable and localised. But why? What is it about the physical properties of sporadic-E layers that drive that propagation behaviour? This presentation will explain what is currently known about the physical nature of sporadic-E, introducing a range of techniques for investigating the ionosphere along the way.