SPRG Seminars
February 19, 2013:
"Metal Resonance Lidar for Investigating Atmospheric Wave Dynamics"
Joe She, Professor Emeritus, Department of Physics, Colorado State University
In this talk, I plan to give an introduction to sodium (Na) resonance lidar with emphasis on its capability for investigating wave dynamics in the mesopause region (80-110 km). To this end, I will begin by briefly presenting the optical processes for lidar probing of atmosphere, and how a Na lidar employs laser induced fluorescence (LIF) spectroscopy to measure upper atmospheric temperature and winds. Using mainly observational examples over Fort Collins, CO (40.6N, 105W), I will then explore: (1) How gravity waves (GWs) influence the climatology of counter-intuitive upper atmospheric temperature (summer colder than winter) and wind (switching directions without heating sources) structures. (2) Observation of a GW breaking event and its aftermath. (3) Challenging observations for the climatology of GW momentum fluxes. Finally, I will mention the problems awaiting for investigations, e.g., wave influences on upper thermosphere, and lidar investigations of tide-GW interactions and turbulence.