SA41A-4052:
Sodium lidar observed gravity wave breaking event and its associated significant sodium sporadic layer
Thursday, 18 December 2014
Chao Ban1, Tao Li1, Xin Fang1, Xiankang Dou1, Jiangang Xiong2, James M Russell III3 and Qian Wu4, (1)University of Science and Technology of China, Hefei, China, (2)Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China, (3)Hampton University, Department of Atmospheric and Planetary Sciences, Hampton, VA, United States, (4)NCAR, Boulder, CO, United States
Abstract:
On the night of July 29th, 2013 (UT day 13210), the University of Science and Technology of China (USTC) sodium temperature/wind lidar, located at Hefei, China (31N, 117E), observed a significant zonal wind shear of -60 m/s/km near ~100 km between 13:15 and 13:30UT, accompanied with a significant cooling near 96-100 km lasting for 1 hr (13:30-14:30 UT). This suggested a significant gravity wave breaking possibly induced by the dynamic instability. The lidar zonal wind is compared with the wind observed by a meteor radar located at Wuhan, ~200 km west of lidar site, and the lidar temperature is compared with SABER temperature, the results further confirmed this possible significant gravity wave breaking event. After the wave breaking, the sodium density was suddenly enhanced by 10-12 times near 94km. Unlike most sporadic sodium layer (SSL) reported in the literatures, this SSL propagated upward, and passed the west lidar beam around 2min earlier than the east lidar beam (~ 50 km separated in the MLT region). The propagate direction of SSL is agreed with enhanced meridional wind observed by Wuhan meteor radar, indicating that this enhanced sodium layer is likely transported from the north of Hefei.
