青南高原汛期降水异常与水汽输送  

Precipitation Anomalies in Flood-Season and Atmospheric Water Vapor Transport over the Southern Qinghai Plateau

作　　者：任雨[1] 张雪芹[1] 李生辰[2] 陶杰[1] 

机构地区：[1]中国科学院地理科学与资源研究所 [2]青海省气象台,青海西宁810001

出　　处：《冰川冻土》2008年第1期35-42,共8页Journal of Glaciology and Geocryology

基　　金：国家重点基础研究发展计划(973计划)项目(2005CB422006);中国科学院知识创新工程领域前沿项目(KZCX2-YW-310);国家自然科学基金项目(40331006)资助

摘　　要：根据地面气象站观测资料,分析1961—2004年青南高原汛期降水变化的区域特征,并依据NCEP/NCAR再分析资料分析了典型多雨和少雨年份的大气水汽输送.研究表明:青南高原汛期降水变化的区域性较强,其东北部、西部和中南部变化形势差异显著,各区典型异常年份出现的时段和频率以及对应的水汽来源不同.其中,来自赤道西太平洋的水汽输送是青南高原东北部地区汛期降水的主要来源,而西北冷空气是降水形成的重要促进因素;西部地区汛期降水主要受到来自孟加拉湾水汽输送和西风水汽输送的影响,同时欧洲东部和西西伯利亚地区阻塞高压活动对其亦有一定影响;中南部地区汛期降水主要来源于西南季风的水汽输送,此外也受到欧亚中高纬环流形势的影响.Regional differences of the flood-season （June, July and August） precipitation over the southern Qinghai Plateau （SQP for short） are examined with observations of 19 surface meteorological stations from 1961 to 2004. Analysis indicates that the precipitation change is characterized by regional differences among the Northeast, the West and the Center-South of the SQP, especially in the occurrence of typical rainy and rainless years. Based on the NCEP/NCAR reanalysis data, atmospheric water vapor transport is explored in the typical rainy and rainless years for the three regions of the SQP. It is concluded that water vapor transported from the western equatorial Pacific Ocean are the main source for the flood-season pre-cipitation of the northeastern SQP, with the northwestern airflow from the middle-high latitudes of Eurasia serving as an important attributing factor. For the western SQP, flood-season precipitation is depended on both the water vapor transported from the Bay of Bengal and the westerlies. Additionally, it is implied that the activity of the blocking high over the East Europe and the West Siberia plays an indispensable role in the precipitation change over this region during the flood season. As to the central and southern part of the SQP, flood-season precipitation is predominated by water vapor transport of the southwest monsoon and affected by the atmospheric circulation patterns over the middle-high latitudes of Eurasia as well.

关 键 词：青南高原 汛期降水 异常 水汽输送 

分 类 号：P426[天文地球—大气科学及气象学]