Study on Clouds in the Hinterland of the Taklimakan Desert Based on Consecutive MMCR Observations

This study mainly focused on the structure and evolution of desert clouds, and was the first to conduct high-resolution consecutive detection of clouds over the hinterland of the Taklimakan Desert (TD) from April to June 2018 using the ground-based Ka-band Millimeter Wave Cloud Radar (MMCR). The reflectivity factor, cloud boundary, and liquid water content (LWC) were calculated based on the power spectrum data observed by the MMCR, which were verified by comparing the detection data of the cloud profile radar (CPR) on the CloudSat board. The results showed that: clouds over the TD were dominated by medium and high clouds, with their thicknesses generally being less than 2 km; moreover, the mean LWCs of the medium and high clouds were less than 0.01 gm−3, which implied that cirrus and stratiform clouds were predominant. However, for the low clouds, the average thickness was 3166 m and the drizzles were concentrated within 2.5 km to 4.5 km, which indicated that precipitation would more likely occur in the low clouds. The mean LWC in the clouds over the TD was 0.0196 gm−3, which was less than that of clean clouds. Compared to the other periods, the average durations and LWCs in clouds increased significantly around noon owing to the obvious surface heating by sensible heat flux. The average duration for the evolution of high to low clouds was approximately 2 h, and the average maximum LWC increased from 0.008 to 0.139 gm−3. These results provide a key database for further studies on the desert cloud structure and the evolution characteristics of clouds over TD.