GC23L-1272
The activities of low level preesure system over the Qinghai-Xizang Plateau and its links with evolution of plateau monsoon
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Zeyong Hu1, Xueyi Xun1,2, Binren Bai1 and Jianli Hao3, (1)CAREERI/CAS Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China, (2)Inner Mongolia Autonomous Region Meteorological Observatory, Hohhot, China, (3)Yuzhongjie Primary School, Lanzhou, China
Abstract:
The activities of low pressure system (LPS) close to land-surface of Qinghai-Xizang Plateau and its links with plateau monsoon index (PMI) and intensity departure of surface heating (B-H) were analyzed based on monthly ECMWF reanalysis data and monthly B-H data. The result shows that the LPS was formed in the southwest of Qinghai Province in April. It moved southwest to Xizang Autonomous Region in May and then shifted to westward. After reached to most west point, the LPS turned back with attenuation and dissipated in October. The intensity of LPS was stronger in high PMI year than that in weak PMI year. The track of LPS located farther north and present less zonal fluctuation in high PMI year. The B-H was well correlated with PMI especially in dry seasons. And there is a time lag of 2 to 3 months. It means that the Plateau summer monsoon onset early and with high intensity at the beginning of the onset period when the thermal effects were strong in February.
