Photo taken on Feb. 11, 2019 shows the cabin of a fluorescence Doppler lidar system at the Zhongshan Station, a Chinese research base in Antarctica. Chinese researchers have installed and tested a fluorescence Doppler lidar system at a research base in Antarctica during a mission that was just concluded last week and are now heading home. The system run at Zhongshan Station had enabled them to simultaneously observe the temperature and the three-dimensional wind field in the atmospheric region mesopause above Antarctica, exploring the middle and upper atmosphere of the polar cusp region. (Xinhua/Liu Shiping)