近42年来青藏高原年内降水时空不均匀性特征分析  

Inhomogeneity Characteristics of Intra-annual Precipitation over the Tibetan Plateau in Recent 42 Years

作　　者：杨玮[1] 何金海[1] 王盘兴[1] 王传辉[1] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室,南京210044

出　　处：《地理学报》2011年第3期376-384,共9页Acta Geographica Sinica

基　　金：国家自然科学基金项目(40633018)~~

摘　　要：根据青藏高原1967-2008年逐日站点降水资料,定义了高原降水集中度(PCD)和集中期(PCP)。并运用EOF、相关分析等方法分析高原PCD和PCP的时空分布特征、PCD与高原强降水的关系以及PCP前期强影响信号。结果表明:高原大部分地区PCD处于0.4～0.8之间,PCP则处于36～41候之间。高原PCD以全区一致型的空间分布为主;而PCP则以南北反向型分布为主,全区一致型分布次之。整个高原PCD均呈减弱趋势,而PCP均表现为提前特征。除高原南侧个别地区,高原PCD无论与高原强降水日数还是强降水量均呈显著正相关。同时,高原南北部PCP对应的水汽输送存在显著差异,高原南部PCP主要受孟加拉湾季风爆发的影响。Based on the daily precipitation datasets from 1967 to 2008 recorded at stations over the Tibetan Plateau,the precipitation concentration degree （PCD） and precipitation concentration period （PCP） of the Plateau are defined.By means of EOF and correlation,as well as spatial and temporal distributions of PCD and PCP,the relationship between PCD and plateau heavy rainfall,and signals of PCP are investigated.The results show that PCD of the plateau area is between 0.4 and 0.8,while PCP is within 36-41 pentads.In space scale,PCD is nearly congruous in the whole region,while PCP manifests a north-south reverse pattern mainly.In time scale,PCD appears to be a subdued tendency when PCP displays an advanced characteristic.Except for a few places in the southern plateau,PCD shows positive correlation with days as well as amounts of intensive rainfall on plateau.In addition,the water vapor transports have significant differences between northern and southern PCP of the plateau,the onset of Bay of Bengal monsoons may have an effect on PCP of the southern plateau.

关 键 词：降水集中度 降水集中期 时空非均匀性 前期信号 青藏高原 

分 类 号：P426.613[天文地球—大气科学及气象学]