The Investigation of Gravity Wave Activities on Mesopause Over Wuhan by Sodium Lidar

The gravity wave activities were investigated based on the data of 26 observation nights from WIPM sodium fluorescence lidar data-base of year 1999 to now. The result shows, the gravity wave activities are very frequent in the mesopause region over Wuhan： in total 185.5 observation hours during 26 nights, 124 gravity wave activities were observed,so that the occurrence frequency of gravity wave activities is about 0.7 activity per hour, and the occurrence has a relationship with local time. The wavelengths of the waves were mainly distributed from 3 km to 7 km, which is consistent with the result reported,and the phase velocities of the waves were maily distributed from 0.1 m/s to 0.5 m/s, which much shower than the reported result. Another feature of the gravity wave activities over Wuhan is that the multiwave activities were much greater than singlewave ones, and the ratio is 3：2. The typical results of the gravity wave propagation and breaking were given through the time and space sequence of relative density disturbence. The gravity wave parameters were also extracted form part of our data throuth the monowave model method.