Climatology Of Interhemispheric Mesopause Temperatures Using The High-Latitude And Middle-Latitude Meteor Radars

We present the climatology of mesopause temperatures using high-latitude and middle-latitude meteor radars. The daily mesopause temperatures are estimated using ambipolar diffusion coefficient data from the meteor radars at Davis Station (68.6 degrees S, 77.9 degrees E), in Antarctica, Svalbard (78.3 degrees N, 16 degrees E), Tromso (69.6 degrees N, 19.2 degrees E) in the Arctic, and Mohe (53.5 degrees N, 122.3 degrees E) and Beijing (40.3 degrees N, 116.2 degrees E) in the northern middle latitudes. The seasonal variations in the meteor radar-derived temperatures are in good agreement with the temperatures from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite. Interhemispheric observations indicate that the mesopause temperatures over the southern and northern polar regions show a clear seasonal asymmetry. The seasonal variations in the Davis Station meteor radar temperatures in the southern polar mesopause are dominated by an annual oscillation (AO) with a relatively weak semiannual oscillation (SAO), which show a clear minimum during summer and a maximum during winter. The mesopause temperatures in the northern high and middle latitudes observed by the Svalbard, Tromso, Mohe, and Beijing meteor radars mainly show an AO, with a maximum during winter and a minimum during summer. The AO in the northern polar regions is stronger than that in the southern polar regions, while the SAO in the southern polar regions is relatively strong compared to that in the northern polar regions.