华北地区降水蒸发差与西太平洋副热带高压的关系  

Correlations between the Precipitation Evaporation Difference in Northern China and the Subtropical High over the Western Pacific

作　　者：孙卫国[1] 程炳岩[2] 郭渠[1] 

机构地区：[1]南京信息工程大学应用气象学院,南京210044 [2]重庆市气候中心,重庆401147

出　　处：《中国农业气象》2010年第1期41-47,共7页Chinese Journal of Agrometeorology

基　　金：国家自然科学基金项目(40675067);南京信息工程大学科研基金(9922)

摘　　要：为揭示华北地区当代水资源受大气内部运动规律制约和海气相互作用的影响,采用小波相关和交叉小波变换方法,分析了华北地区降水蒸发差与西太平洋副热带高压脊线和北界位置变化的时频相关。结果表明,2000年以来华北南部的水资源短缺问题有所缓解,但以北京为中心的华北东北部仍处于持续缺水期;华北地区降水蒸发差与副高脊线及北界位置变化相关密切,存在年际和年代际尺度的显著相关振荡,与副高脊线的年代际尺度相关凝聚性最强;时域中年际尺度相关存在局部化特征,年代际尺度相关具有阶段性。分析认为,2000年以来副高脊线和北界位置偏北并维持反气旋型环流,有利于水汽向华北输送,使得华北降水增多成为近年来华北南部降水蒸发差增大的主要原因;而华北东北部仍处于持续缺水期,与东亚季风减弱不利于西南气流的水汽输送以及蒙古高原显著增暖导致蒸发增大等因素有关。副高强度和位置异常影响东亚季风强度和西风带槽脊位置引起华北降水和气温变化发生异常,对华北地区降水蒸发差的年际和年代际变化具有重要作用。To reveal the restrictions of atmospheric general circulation and the effects of interaction between atmosphere and ocean on the water resources in Northern China, the relationship between the movement of subtropical high （STH） location over the Western Pacific and the difference of precipitation and evaporation （DPE） in Northern China were analyzed by using the method of wavelet cross-correlation and cross wavelet transform. The results showed that the wa- ter resource shortage was relieved in the south of Northern China since 2000, but not changed in the north of Northern China including Beijing. There were significant correlation oscillations of inter-annual and inter-decadal scale between the DPE in Northern China and the location of STH ridge line and northern limit, and the coherence of inter-decadal correlation between the DPE and the STH ridge line was higher than the coherence of inter-decadal correlation between the DPE and the STH northern limit. The significance of inter-decadal correlation was exhibited at a stage and the in- ter-annual correlations were localized in the time space during 1955 to 2008. The results indicated that the main reason of the increasing of DPE in the south of Northern China since 2000 was increasing precipitation in the region, which resuited from the STH ridge line north-extending and keeping as anticyclonic circulation. The abnormal intensity and location of the STH had obvious effects on the inter-annualand inter-decadal variations of the DPE in North China.

关 键 词：华北地区 降水蒸发差 副热带高压 交叉小波变换 

分 类 号：S161.6[农业科学—农业气象学]