Meteor trails and columniform sprites

A theoretical model of columniform sprites (or c-sprites), a distinctive cl ass of high altitude, temporally brief optical emissions, is presented and compared to observations which extends earlier work (1998, E. M, D, Symbali sty, R, Roussel-Dupre, and V. Yukhimuk, EOS Transactions of the AGU 79, No. 45, p, F129) by making a strong connection with meteors, The key features of the model are: (1) an ambient conductivity profile that falls between a measured nighttime and a measured daytime conductivity; (2) an aerosol redu ced conductivity in a trail from a meteor that passed through some time dur ing the evening, and (3) a cloud-to-ground (hereafter CG) lightning stroke, with sufficient charge transfer, subsequent to and occurring within an hou r of the development of the reduced conductivity trail. The model predicts a temporally brief column oh light resulting from the conventional breakdow n of air in a strong electric field in the observed altitude range. For the case of a positive CG stroke the emissions are extinguished by the passage of a runaway electron beam. The electron beam is initiated by the same pos itive CG lightning stroke that allows the high altitude conventional breakd own to occur and propagates from the cloud tops to the ionosphere, Based on our modeling results, a negative CG lightning stroke, for the same amount of charge transfer, produces a column of light about twice as bright. The e missions are extinguished, in this case, by the ambient conductivity taking into account the increase due to the conventional breakdown of air. In bot h cases, for the CG lightning stroke parameters examined here, the simulate d c-sprite emissions are brief and last less than 17 ms, or one CCD video f ield. (C) 2000 Academic Press.