Fig. 4
From: Topside equatorial spread F-related field-aligned Poynting flux: observations and simulations

The four panels show EPD-related mean Poynting flux \(|\mathbf {\overline{S}}_\parallel |\) as a function of the depletions’ depth relative to the background \(\delta n/n_0\) in a and c, and depletions’ depth \(\delta n\) in b and d. The rows indicate pre- and post-midnight EPDs