%0 Journal Article %A LIU Jia %A YANG Rong %A LUO Yu %A MA Zhenfeng %A CHEN Chao %A LI Xiaolan %T Variation Characteristics of Extreme Precipitation in Midsummer in Sichuan and Relationship with Tibetan Plateau Summer Monsoon %D 2018 %R 10.11755/j.issn.1006-7639(2018)-05-0733 %J Journal of Arid Meteorology %P 733-742 %V 36 %N 5 %X

Based on the daily precipitation data of 156 weather stations in Sichuan Province and NCEP/NCAR reanalysis data, the temporal and spatial distribution characteristics of extreme precipitation events in midsummer in Sichuan Province and their relationship with Tibetan Plateau summer monsoon were analyzed during 1961-2015. The results show that the climate tendency rate of extreme precipitation indexes in midsummer in Sichuan had an obvious spatial difference during 1961-2015, PPER decreased in most areas of Sichuan, while PRCPTOT, R95p, SDII, RX1day and RX5day mainly appeared a decreasing trend in western Sichuan basin and the northwestern part of the plateau of western sichuan and an increasing trend in other regions in recent 55 years. From the whole area of Sichuan Province, the decreasing trend and mutation of PRCPTOT in midsummer were not obvious during 1961-2015, while the decreasing trend of PPER was significant with an obvious mutation in 1985. SDII and R95p in midsummer increased significantly on the whole and happened obvious mutation in 1980 and 1990, respectively, while RX1day and Rx5day increased non-significantly and happened three obvious mutations. The extreme precipitation indexes in midsummer in Sichuan had 3 to 4 years and 8 years periods oscillation from 1961 to 2015. The extreme precipitation in midsummer in the east and west of Sichuan basin was closely related with the anomaly of Tibetan Plateau summer monsoon. When the Tibetan Plateau summer monsoon was strong, the meridional circulation was dominant over the middle and high latitude areas of East Asia on composited 500 hPa geopotential height anomaly field. At the same time, the western Pacific subtropical high was southward, and the southwesterly wind and water vapor from the Bay of Bengal strengthened, which was beneficial to more (less) extreme precipitation in the east (west) part of Sichuan basin in midsummer. However, when the Tibetan Plateau summer monsoon was weak, the situation was the opposite.

%U http://www.ghqx.org.cn/EN/10.11755/j.issn.1006-7639(2018)-05-0733