1976年大气环流突变前后中国四季降水量异常和温度的年代际变化及其影响因子  

The interdecadal contrast characteristics of the rainfall and temperature in China around the atmospheric circulation carastrophe in 1976 and its affecting factors

作　　者：李春晖[1] 万齐林[1] 林爱兰[1] 谷德军[1] 郑彬[1] 

机构地区：[1]中国气象局广州热带海洋气象研究所,中国气象局热带季风重点实验室,广州510080

出　　处：《气象学报》2010年第4期529-538,共10页Acta Meteorologica Sinica

基　　金：国家重点基础研究发展计划项目(973项目,2006CB403600);广东省科技计划项目(2005B32601007);国家自然科学基金(90211010,40775058,40675054,40675055,40505019);广东省自然科学基金(06020745)

摘　　要：利用NCEP/NCAR全球2.5°×2.5°月平均再分析资料和中国国家气候中心(NMC)提供的743站降水和温度资料分析了1976年大气环流突变前后中国四季降水量异常和温度的年代际对比特征,发现1976年后,春季中国华南降水偏多、温度偏低,长江流域西部降水偏少、温度偏低。夏季降水主要呈现华南少、长江流域多、华北少和东北多的"-、+、-、+"的分布形势,温度表现为华南增暖、长江淮河流域冷却和北方增暖的分布特征。秋季中国大部分地区降水量异常是减少的、温度是上升的。冬季华南地区降水量异常虽有增加但不显著,整个中国区域几乎呈增暖趋势。中国平均温度的年代际变化在春季和夏季的降温主要受最高温度变化影响、升温主要受最低温度影响;秋季的整体增暖受最低温度影响更大,而冬季的整体增暖受最高温度影响更大。造成以上变化的原因与1976年大气环流突变前后,四季哈德来环流上升支和下沉支的南北推移、西风急流的增强和位置的南北移动、大气层结的干湿状况以及水汽输送的来源密切相关。The interdecadal contrast characteristics of rainfall and temperature in China around 1976 and its affecting factors are analyzed by using the NCEP/NCAR reanalysis data and the surface air temperature/rainfall records from the 743 stations in China.The results show that,since 1976,the rainfall and the temperature in South China has been increased and decreased in spring,respectively,whereas the rainfall over the west part of the Yangtze River valley decreased.In summer,there existed a meridional＂＋,-,＋,-＂precipitation pattern in which there are more rains in South China and North China but less rains in the Yangtze and Huaihe River basins and Northeast China.It was found that a strong cooling occurs in the Yangtze River and the Huaihe River valleys in contrast to warming in the other regions in summer.The mean temperature in China shows an increasing trend evidently and the total amount of rainfall has a decreasing trend obviously in autumn.In winter,the consistent warming trend was showed almost in the whole China and an excessive rainfall in South China and the Yangtze River valley. The interdecadal decline of mean temperature in China is mainly due to the maximal temperature variation,while the rise mainly to the minimal temperature in and spring summer.The warming in fall and winter is mostly influenced by the minimal and maximal temperature variations,respectively.Possible causes for the interdecadal contrast change of the rainfall and temperature in China were closely related with the shift of the ascending and subsidence branches of the Hadley circulation,the intensification and migration of the westerly jet,the dry-wet conditions of the atmospheric layer,as well as the origin of water vapor transport.

关 键 词：中国降水和温度 季节变化 哈德来环流 西风急流 水汽输送 

分 类 号：P434[天文地球—大气科学及气象学] P423