东亚—北太平洋大气环流和瞬变扰动的年代际变化  

Interdecadal variations of atmospheric circulation and synoptic-scale transient eddy activities over the East Asian-North Pacific

作　　者：蒋伶仙[1] 任雪娟[1] 杨修群[1] 

机构地区：[1]南京大学大气科学学院,南京210093

出　　处：《气象科学》2011年第5期549-557,共9页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(40730953和40775044)

摘　　要：用NCEP/NCAR再分析资料,分析了东亚—北太平洋大气环流、大气斜压性和天气尺度瞬变扰动活动的年代际变化特征。东亚—北太平洋地区低层大气温度和比湿及高层的西风急流都存在明显的年代际变化。西风年代际异常与大气斜压性年代际异常之间有密切联系。夏季北太平洋北部到西伯利亚高原上空的天气尺度瞬变扰动活动年代际增强,但夏季低层瞬变热力和瞬变水汽强迫的年代际异常对北太平洋中纬度低层平均温度和比湿年代际异常的作用并不显著。冬季,西太平洋西风急流年代际增强与急流下方大气斜压性年代际增加相一致,使该地区瞬变扰动年代际增强,增强的瞬变扰动将更多能量传送给西风气流,巩固了西风急流的年代际异常。年代际尺度上冬季异常的瞬变热力强迫和瞬变水汽强迫对低层大气温度和比湿异常有显著的削弱作用。Based on NCEP/NCAR reanalysis data,the interdecadal variations of atmospheric circulation,eddy growth rate maximum（σBI）and synoptic-scale transient eddy activity（STEA）over East Asian-North Pacific region are investigated.The air temperature,water vapor in the low troposphere and the Western Pacific westerly jet stream（WPJS）in the high troposphere over East Asian-North Pacific show obvious interdecadal variability.The WPJS interdecadal anomaly is closely related to the interdecadal changes of σBI.In summer the STEA is strengthened from the North Pacific to the Siberian Plateau on the interdecadal time scale.However,the associated low-level eddy thermal forcing and eddy moisture forcing do not show significant effect on the interdecadal anomalies of mean air temperature and water vapor in the middle latitude Pacific.In winter the WPJS is strengthened interdecadally accompanied with the increasing of σBI underneath the WPJS.This causes intensified STEA on the interdecadal time scale.The strengthened STEA delivers more energy to the westerly wind.Thus it reinforces the WPJS anomaly.In winter the low-level eddy thermal forcing and eddy moisture forcing show evidence of damping effect on the air temperature and water vapor anomalies in the lower troposphere on the interdecadal-scale.

关 键 词：大气环流 天气尺度瞬变扰动活动 年代际变化 

分 类 号：P461[天文地球—大气科学及气象学]