21st Conference on Climate Variability and Change


Analyzing occurrences and vertical structures of hydrometeors over the Asian summer monsoon regions and the Tibetan Plateau region using CloudSat/CALIPSO data

Yali Luo, Chinese Academy of Meteorological Sciences, Beijing, , China; and R. Zhang and H. Wang

The occurrence frequency, vertical location, and vertical distribution of radar reflectivity factor (dBZ) of hydrometeors covering the Eastern Asian Summer Monsoon Region (EASMR), Indian Summer Monsoon Region (ISMR), Western North Pacific Summer Monsoon Region (WNPSMR), and the Tibetan Plateau Region (TPR) are described using two CloudSat standard products (2B-GEOPROF and 2B-GEOPROF-LIDAR) during the period of July 2006-August 2007. During the period, the hydrometeor occurrence frequencies are 72% (EASMR), 76% (ISMR), 84% (WNPSMR), and 68% (TPR), respectively, to which single-layer hydrometeors contribute 53% (ISMR and WNPSMR) to 77% (TPR). The multi-layer hydrometeors are mostly double- or triple-layered. There is a significant seasonal variation in total hydrometeor amount at ISMR, but not at the other regions. The hydrometeor layers are geometrically thin at the four regions, with 29-37% being thinner than 1 km. The separation distance between two consecutive layers in multilayered hydrometeors has about 10% less than 1 km. High cloud containing small ice crystals is the most prevalent cloud type at the ISMR and WNPSMR all over the year. Marine boundary layer clouds are common all over the year at the WNPSMR, in contrast to the ISMR where low-level hydrometeors occur mainly during summer. The EASMR hydrometeors are located mainly at the middle and low troposphere from autumn to spring. Although more hydrometeors appear at the upper troposphere during summer than other seasons at the EASMR, they are located lower compared to those at the ISMR and WNPSMR. The TPR hydrometeors are mostly located at the middle troposphere, consisting of particles with varying sizes. The dBZ-altitude frequency distributions of deep convection significantly differ between the TPR and the Asian summer monsoon regions.

Session 5, Monsoons - II
Tuesday, 13 January 2009, 11:00 AM-12:00 PM, Room 129A

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