《Argall-2016-Sodium》.pdf

Lidar measurements taken with a large-aperture liquid mirror. 2. Sodium resonance-fluorescence system P. S. Argall, O. N. Vassiliev, R. J. Sica, and M. M. Mwangi Sodium resonance-fluorescence lidar is an established technique for measuring atmospheric composition 2 and dynamics in the mesopause region. A large-power–aperture product 6.6-W m sodium resonance- fluorescence lidar has been built as a part of the Purple Crow Lidar PCL at The University of Western Ontario. This sodium resonance-fluorescence lidar measures, with high optical efficiency, both sodium density and temperature profiles in the 83–100-km region. The sodium lidar operates simultaneously 2 with a powerful Rayleigh- and Raman-scatter lidar 66 W m . The PCL is thus capable of simultaneous measurement of temperature from the tropopause to the lower thermosphere. The sodium resonance- fluorescence lidar is shown to be able to measure temperature to an absolute precision of 1.5 K and a statistical accuracy of 1 K with a spatial–temporal resolution of 72 km s at an altitude of 92 km. We present results from three nights of measurements taken with the sodium lidar and compare these with coincident Rayleigh-scatter lidar measurements. These measurements show significant differences between the temperature profiles derived by the two techniques, whic