Sodium Temperature Lidar for Probing the Upper Atmosphere over Antarctica.

We describe the development of a new sodium temperature lidar for probing the upper atmosphere over Antarctica. The laser transmitter consists of two injection-seeded Nd:YAG lasers with wavelengths of 1064 nm and 1319 nm. A narrow-band pulsed laser tuned to the sodium D2 line (589 nm) is created by sum frequency generation of 1064 nm and 1319 nm laser pulses. The resulting laser pulse has a line width of less than 100 MHz. The two-frequency technique for measuring the temperature profile in the mesospheric sodium layer is evaluated by comparison with the Doppler profile-fitting technique and results show good agreement. Moreover, based on lidar data obtained at Syowa station, Antarctica in 2000, it is shown that the sodium temperature lidar is a powerful tool for probing the temperature profile in the mesosphere and lower thermosphere region as well as the stratosphere.