Analysis of cirrus cloud over the Tibetan Plateau from CALIPSO data: an altitude perspective

Abstract. Using the 5-year summer Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data, the geographical distributions of cirrus over the Tibetan Plateau have been studied according to the cloud top height. The cirrus number at the corresponding heights exhibit striking differences over the plateau. The maximum occurrence for cirrus top below 9 km starts over the western plateau and moves up to the northern regions when cirrus is between 9–12 km. Above 12 km, the maximum occurrence of cirrus retreats to the southern fringe of the plateau. These characteristics are linked to three kinds of formation mechanisms: large-scale orographic uplift, ice particles generation caused by gravity wave and remnants of overflow from deep convective anvils, respectively.