VLF SCATTERING FROM RED SPRITES - THEORY

A relatively simple model of Red Sprites as a set of conducting column s reproduces the radio physics properties of VLF sprites. The columnar structure of optical sprites is represented by thin vertical conducti ng columns (or 'Spritelets') in free space, with dimensions taken from optical observations. The scattered field from a set of coupled Sprit elets has a complex amplitude pattern which normally includes some dee p minima reproducing the 'perturbation shadows' seen in some experimen tal events. It is not uncommon for the back scattered amplitudes to be similar to those for forward scatter in the theoretical model, as in experimental reports. As some sprite events appear to have closely spa ced Sprite:ets, the results presented here indicate that there will be a high degree of electrical shielding. This is an application of the theory presented by Rodger et al. (1997a). (C) 1998 Elsevier Science L td. All rights reserved.