Mesospheric Na Wind/Temperature Lidar

Abstract

Meteoric ablation in the upper atmosphere is the source of a dense layer of atomic Na between 80-105 km with maximum densities averaging 4×10³ cm^-3. The Na layer is a sensitivetracer of the wind, thermal, and density structure of this region and can be probed with exceptionalaccuracy and resolution using resonance fluorescence lidar techniques. Modern narrowbandtunable lasers are now being used in Na lidar systems to measure routinely winds andtemperatures with accuracies approaching ±1 m/s and ±1 K. We describe the Na Wind/Temperature lidar technique and present examples of observations made during the recent ALOHA-93 Campaign in Hawaii.