Lidar Soundings of Gravity Waves in the Middle Atmosphere above South Pole

Abstract

We report on the first soundings of the Temperature Lidar for the Middle Atmosphere (TELMA) which was deployed to the Amundsen–Scott South Pole Station in February 2023. TELMA measures temperature profiles up to about 90 km altitude and thus bridges the vertical gap between past stratospheric lidar observations and current airglow observations of gravity waves. During the first winter season, TELMA acquired a large data set totaling 614 h. We show examples of gravity waves identified in lidar data in the upper mesosphere reaching amplitudes of ~10 K and discuss potential influences from both the polar vortex dynamics and catabatic winds across the Transantarctic Mountains. Our data suggest that gravity waves at South Pole have typically lower potential energy densities and show different characteristics compared to gravity waves observed by TELMA’s twin instrument CORAL located near the edge of the polar vortex at the tip of the Southern Andes. The different behavior may be attributed to different wave generation mechanism at the two locations as well as differences in the propagation conditions.