Seasonal variation of meteor decay times observed at King Sejong Station (62.22°S, 58.78°W), Antarctica

Abstract

We analyzed meteor decay times measured by a VHF radar at King Sejong Station by classifying strong and weak meteors according to their estimated electron line densities. The height profiles of monthly averaged decay times show a peak whose altitude varies with season at altitudes of 80~85 km. The higher peak during summer is consistent with colder temperatures that cause faster chemical reactions of electron removal. By adopting temperature dependent empirical recombination rates from rocket experiments and meteor electron densities of 2x10^5 ~ 2x10^6 cm^3 in a decay time model, we are able to account for decreasing decay times below the peak for all seasons without invoking meteor electron removal by hypothetical icy particles.