千年时间尺度南亚高压和西太平洋副热带高压关系的时空变化特征  

THE SPATIAL AND TEMPORAL VARIATION CHARACTERISTICS OF THE SOUTH ASIA HIGH AND WESTERN PACIFIC SUBTROPICAL HIGH ON MILLENNIAL TIME SCALE

作　　者：王宁[1,2] 张肖剑[2] 靳立亚[2] 

机构地区：[1]兰州大学大气科学学院,兰州730000 [2]兰州大学资源环境学院,兰州730000

出　　处：《第四纪研究》2015年第6期1425-1436,共12页Quaternary Sciences

基　　金：国家自然科学基金项目（批准号：41275071和41130102）和全球变化研究重大科学研究计划项目（批准号：2010CB950202和2010CB950204）共同资助

摘　　要：利用全新世的气候模拟结果（KCM）以及1948 ～ 2013年NCEP/NCAR逐月再分析资料,分析了大型大气环流系统南亚高压和西太平洋副热带高压（以下简称＂西太副高＂）在千年时间尺度上的特征和它们之间的空间位置变化关系以及与东亚夏季风的关系,并比较了它们与现代气候背景年际时间尺度变化特征的异同.结果表明,在千年尺度上,南亚高压的东进（西移）对应西太副高的西伸（东撤）.这与年际尺度上南亚高压与西太副高存在的＂相向而行＂及＂相背而去＂的时空特征是一致的.耦合气候模式模拟的全新世9.5ka B.P.以来东亚夏季风总体呈现振荡减弱趋势.早全新世（9.5～7.5kaB.P.）时期,东亚夏季风强度较强,此时南亚高压位置偏东而西太副高位置偏西;在中全新世（7～4ka B.P.）期间,东亚夏季风呈现百年尺度大幅振荡,而此时南亚高压（西太副高）的位置大致位于112＆#176;～115＆#176;E（145＆#176;～155＆#176;E）之间;晚全新世（4～0ka B.P.）期间,东亚夏季风持续减弱,对应南亚高压位置向东移动、西太副高位置向西移动.全新世时期（9.5～0ka B.P.）,北半球春季（4月、5月份）赤道地区接收的太阳辐射呈现先减弱,至5～4ka B.P.期间达到最低值,之后逐渐增强的变化趋势,这与南亚高压的位置变化趋势一致,而与西太副高位置变化趋势相反,即赤道春季太阳辐射强（弱）时,南亚高压位置偏东（偏西）、西太副高位置偏西（偏东）.同时,模拟的全新世热带印度洋-西太平洋夏季温度变化也呈现出与春季赤道太阳辐射一致的变化趋势,且与南亚高压有显著的正相关关系,海温的加热作用可以通过激发Matsuno-Gill型大气响应使得南亚高压增强.西太副高主要由哈德莱环流在副热带地区的下沉作用造成,而热带印度洋-西太平洋夏季的增温可引起哈德莱环流增强,从而使西太副高的强度�The Western Pacific subtropical high （WPSH） and South Asian high （SAH） are closely related to the East Asian summer （June-July-August, JJA） monsoon （EASM）. Previous researches found a close relationship between the WPSH and SAH on the inter-annual time scale in present-day climate. However, their behaviors and relationship are rarely discussed on millennial time scale during the Holocene. In this study, we explore the spatial and temporal variation characteristics of the WPSH and SAH on millennial time scale for the period of Holocene from 9.5ka B.P. to 0ka B.P. using the model results from a series of numerical experiments in an atmosphere- ocean-sea ice coupled climate model, the Kiel Climate Model （KCM）. The simulations include two time-slice equilibrium experiments for Early Holocene （9.Ska B.P. ） and present-day （0ka B.P. ）, respectively and one transient simulation （HT） using a scheme for model acceleration regarding to the Earth＇s orbitally driven insolation forcing for the whole period of Holocene （from 9.Ska B.P. to 0ka B.P. ）. In addition, the National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） Reanalysis dataset is used in this study to compare with the model results. The model results show an eastward extension of the WPSH before 5ka B.P. and a westward extension after then. The behavior of the SAH showed a complete opposite trend with the WPSH, displaying a westward shift before 5ka B.P. and an eastward shift after then. The contrast in the behavior between the WPSH and SAH on millennial time scale during the Holocene resembles to that on inter-annual time scale in present-day climate. The model results show that the stronger EASM during the Early Holocene （9.5-7.5ka B.P. ） was accompanied by a gradual westward （eastward） shift of the SAH （WPSH）. In the Mid-Holocene （7.4ka B.P. ）, the EASM shows a multi-centennial time scale oscillations with the SAH （WPSH） relatively located between 112°- 1

关 键 词：全新世 南亚高压 西太副高 太阳辐射 东亚夏季风 

分 类 号：P467[天文地球—大气科学及气象学] P534.632