Climate Features Of Summer Precipitation In ChongQing Region And Related Ocean-atmosphere Background Analysis

Based on 160 stations' monthly precipitation in China, summer rainfall in ChongQing region, NCEP/NCAR reanalysis dataset, the temporal and spatial features of summer rainfall anomaly in ChongQing region and related circulation background are studied. Furthermore, the teleconnection relationship between SSTA of south pacific and rainfall anomaly in ChongQing is analyzed. At last, grey systems are applied to build the disaster precipitation model focused on the summer drought and flood in Chongqing region.The results show:(1) The summer rainfall in ChongQing region exhibits upward tendency (i. e. the remarkable tendency of moist weather) in recent 40 years, wholly or regionally. Cycle variations of quasi-16a, 8-10a and 4-6a prevails in the summer rainfall in ChongQing for the whole 40a period, and so are the short cycle of 2-4a prior 1980s. The interdecadal features of summer rainfall in Chongqing are modest drought during 1960s, severe drought during 1970s, severe moisture during 1980s and modest moisture during 1990s. The summer precipitation in ChongQing is in phase with the rainfall in the middle and low reaches of Yangtze river, and out of phase with the rainfall in Southern China, Northern China and Sichuan Basin.(2) The 40a summer precipitation in ChongQing region presents the types of entire flood, entire drought, north-flood and south-drought, north-drought and south-flood, west-drought and east-flood, west-flood and east-drought. Spatially, four sensitive regions are further classified as northwest-Yu, northeast-Yu, southeast-Yu and southwest-Yu.(3) During the period from 1960a to 2000a, 6 years are selected out as abundant summer rainfall years and 7 years as meager summer rainfall years. The synthesized analyses of these years indicate that the...