The laser radar system for measurement of the middle atmosphere at Syowa Station in Antarctica

Multiwavelength laser radar system was installed at Syowa Station in 1983 by the 24th Japanese Antarctic Research Expedition for measurement of the middle atmospheric phenomena in cooperation with International Middle Atmosphere Program (MAP). The laser radar can simultaneously shoot two kinds of laser pulses (0.6943μm : the fundamental wave, 0.3471μm : the second harmonic wave) by means of ruby laser with regulated repetition frequencies (maximum : 1Hz) and receive scattered light by a telescope with the 50 cmφ-lens in efficient diameter. The measurement can be done by using a photon counter for each wave and A-scope for the fundamental wave. The test observation had been successfully made in Japan and it showed the remarkable increases of the strato-spheric aerosol due to the volcanic eruption of Mt. El Chichon. It was also inferred that the size distribution of the particles in the aerozol layer is inhomogeneous.