Possible mechanisms of summer cirrus clouds over the Tibetan Plateau Feng Zhang1,2, Qiu-Run Yu3, Jia-Li Mao4, Chen Dan4, Yanyu Wang4, Qianshan He6,7 , Tiantao Cheng 1, Chunhong Chen6, Dongwei Liu6, Yanping Gao8 5 1Department of Atmospheric and Oceanic Sciences, Institute of Atmospheric Sciences, Fudan University, Shanghai, China; 2Innovation Center of Ocean and Atmosphere System, Zhuhai Fudan Innovation Research Institute, Zhuhai, China; 3Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, Quebec, Canada 4Key Laboratory of Meteorological Disaster, Ministry of Education, Nanjing University of Information Science and 10 Technology, Nanjing, China 5Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai, China; 6Shanghai Meteorological Service, Shanghai, China; 7Shanghai Key Laboratory of Meteorology and Health, Shanghai, China; 15 8Shanxi Institute of Meteorological Sciences, Taiyuan, China Correspondence to: Qianshan He (
[email protected]) Abstract. The geographical distributions of summertime cirrus with different cloud-top heights above the Tibetan Plateau are investigated by using the 2012 - 2016 Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) 20 data. The cirrus clouds with different cloud top heights exhibit an obvious difference in their horizontal distribution over the TP. The maximum occurrence for cirrus with cloud top height less than 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. Three kinds of formation mechanisms: large-scale orographic uplift, ice particles generation caused by temperature fluctuation, and remnants of overflow from deep convective anvils dominate the formation of cirrus 25 less than 9km, between 9-12 km and above 12 km, respectively.