Seasonal Temperature Variation of the MLT Region Inferred from A VHF Meteor Radar at King Sejong Station, Antarctica

Abstract

A VHF meteor radar at King Sejong Station(62±S, 59±W), Antarctica has been observing meteors more than 20,000 per day since March, 2007. Meteors entering the earth's atmosphere may reveal much information on the atmospheric temperatures and wind fields of the mesosphere and lower thermosphere (MLT), especially the altitude region between 80km and 100km. The temperature information can be inferred from diffusion coefficients that are derived from observed meteor decay times. In this study, we present the altitude profiles of 15-min. averaged diffusion coefficients for each month of Austral fall, spring, and summer 2007. From our results, we found that there is a clear seasonal change in altitude profiles of diffusion coefficients, namely the well known characteristics that the mesopause altitude rises and falls during summer and winter, respectively. We will discuss some implication of this seasonal change in the MLT temperature profiles at the southern high latitude and compare our results with TIMED/SABER temperature profiles. We also present the monthly averaged values of temperature-pressure parameters derived from the diffusion coefficients, and compare them with those of other meteor observations at northern mid(43±N) and low(8.5±N) latitudes.