EOMF-27. Analyzing Lidar Observations over McMurdo, Antarctica to Investigate Vertical Development of Gravity Wave Energy in the Stratosphere and Mesosphere
Lidar systems provide unrivaled monitoring of the middle atmosphere, allowing for high-temporal and spatial resolution measurements of atmospheric parameters and constituents, which enable the observation of gravity wave properties such as wave energy and constituent/heat/momentum fluxes. The Arrival Heights lidar observatory has been collecting data above McMurdo, Antarctica for over 10 years, measuring the middle and upper atmosphere. Within this data are high-resolution gravity wave measurements, enabling the study of wave-induced energy-dynamics in the atmosphere, a key task in improving the performance of general circulation models and for fully understanding the role of the polar atmosphere. Utilizing powerful new methods which eliminate bias in the measurements (previously a major obstacle to this sort of study), this work looks at the development of gravity wave energy through the stratosphere and the mesosphere, with the goal of improving our understanding of the interaction between these waves and the background field. Both statistical and case studies are performed, focusing on characterizing energy diffusion/dissipation processes. The data is analyzed to identify signals of wave-breaking-induced secondary gravity waves and these cases are documented and studied to compare their characteristics with other known cases and with existing theory to help determine the behavior of these secondary-waves. Preliminary results have revealed near-continuous growth of gravity wave potential energy density (Epm) from the stratosphere to the lower-thermosphere, contradicting previous studies which suggested there may be a major dissipative process present in the region. Vertical profiles of Epm covering 30-70 km and 80-105 km are produced for the Antarctic winter, and Epm from 30-50 km is produced for the winter, spring, and fall seasons. Seasonal differences between these Epm values and growth rates are analyzed to identify any variation in the dissipative processes.