Low frequency electromagnetic radiation from sprite streamers

Formation of sprite streamers at subbreakdown conditions from ionospheric inhomogeneities resembling observed sprite halo structures

[1] Modeling results of sprite streamer formation from large ionospheric inhomogeneities or patches (several tens to hundreds of meter wide) indicate that positive streamers can be initiated at subbreakdown conditions from the inhomogeneities with a density comparable to sprite halo densities. For spherical patches with a given radius, the minimum density required for streamer initiation decrea...

Radio Frequency Electromagnetic Radiation From Streamer Collisions

We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer colli...

Low-Frequency Electromagnetic Scattering

The main result of this paper is to reduce the calculation of higher-order terms in the asymptotic expansions of the electric and magnetic elds at low frequencies to the solutions of certain canonical problems. We also provide a new and simple variational proof of the convergence of the electric and magnetic elds solutions of the scattering problem for the Maxwell equations as the frequency goe...

Effects of Propagation on the High-frequency Electromagnetic Radiation from Low-altitude Nuclear Explosions

Emergence of sprite streamers from screening-ionization waves in the lower ionosphere

Sprite discharges above thunderclouds at altitudes of 40–90 km (refs 1–5) are usually created by a strong positive cloud-to-ground lightning flash6. Sometimes these sprite discharges emerge from a visible halo5,7–9, and during the first stage they always propagate downwards and branch on their way5,7,9–11. Modelling efforts have been restricted to conditions of non-ionized air of constant densi...