Lidar Observation of Mesospheric Clouds Above Beijing: A Case Study

¹ School of Physics and Electronics Engineering, Hainan Normal University, Haikou, 571158, China ;
² State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing, 100190, China
³ College of Mathematics and Information Science, Henan Normal University, Xinxiang, 453007, China

^* shhgong@hainnu.edu.cn

Published online: 7 July 2020

Abstract

We report on the first observation of mesospheric cloud (MC) at the altitude range of 50-65 km with lidars at Yanqing (40.5°N, 116°E) and Pingquan (41°N, 118.7°E) on 30 October 2018. The MC occurred at the 51-56 km altitude range during the hours of dawn. It had an obvious double-layer structure, but the cloud layer was sparse. The MC was re-observed at the 56-62 km altitude range in the twilight, and the double-layer structure was still obvious. However, the cloud layer became thicker with a maximum volume backscatter coefficient (BSC) 3.1×10⁻¹⁰m⁻¹sr⁻¹. Atmospheric temperature structure was derived according to the lidar observations, and it was found that, several hours before the MC occurrence, a temperature anomaly with coldest temperature ~185 K was propagating downward at the altitudes of 50-65 km. This MC layer was simultaneously observed with lidar at Pingquan in the twilight. It could be a regional MC event and possibly formed locally by a transient cooling due to small-scale disturbances in the mesosphere.