不同年代际背景下南半球冬季马斯克林高压影响因子的比较  

Comparison of factors impacting the Mascarene High during austral winter against different interdecadal backgrounds

作　　者：徐海明[1,2] 周备[1,2] 

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,江苏南京210044 [2]南京信息工程大学大气科学学院,江苏南京210044

出　　处：《大气科学学报》2017年第2期202-214,共13页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(41275094;41490643;41575077);国家重点基础研究发展计划"973计划"项目(2012CB955602);江苏高校优势学科建设工程项目(PAPD);江苏省高校"青蓝工程"

摘　　要：利用NCEP/NCAR与ERA-40再分析资料分析了南半球冬季(JJA)马斯克林高压的年际和年代际变化特征,并重点讨论了不同年代际背景下影响马斯克林高压年际变化因子的变化。结果表明,冬季(JJA)马斯克林高压的强度在1976年前后发生了显著的年代际转折,1976年以前强度偏弱,1976年以后强度明显增强。进一步分析显示,影响马斯克林高压年际变化的因子同样也发生了年代际转折。在1976年以前,冬季马斯克林高压与印度洋局地海温和南极涛动(Ant Arctic Oscillation,AAO)表现出显著的相关性;而在1976年以后,冬季马斯克林高压与ENSO和AAO表现出显著的相关性。同时,印度洋局地海温与马斯克林高压的相关性减弱,而ENSO与马斯克林高压的相关性则显著增强。Based on NCEP/NCAR and ERA-40 reanalysis data, interannual and interdecadal variations of the Mascarene high are analyzed, with specific focus on exchanges in the factors affecting the interannual variability of the Mascarene high against different interdecadal backgrounds.In order to investigate the intensity of the Mascarene high on different timescales, a Mascarene high area index（MHI） is defined to represent the intensity of the Mascarene high.Results show that significant changes of the Mascarene high are apparent on different timescales. On the seasonal timescale,the intensity of the Mascarene high is largest in summer,with its position in the west; whereas ,the intensity is weakest in winter,with its position in the east.In the long-term trend,the intensity of the Mascarene high in the four seasons presents a significant linear increasing trend, with its trend strongest in spring and weakest in winter.On the interdecadal timescale,the four seasons experienced a marked interdecadal shift around 1976, characterized by a weaker Mascarene high before 1976 and a significantly strengthened one after 1976. The latest research results,both here and abroad, show that there are three possible factors affecting the Mascarene high ： the local sea surface temperature （ SST ） over the southern Indian Ocean, the Antarctic Oscillation （AAO）, and the E1 Nino-Southern Oscillation （ENSO）.On the basis of these achievements, we put out two questions：What are the main factors affecting the Mascarene High？ And has the relationship between the Mascarene high and its affecting factors changed since 19767 To answer these questions ,regression analysis and correlation analysis are adopted.The results show that the factors affecting the interannual variability of the Mascarene high are different during these two periods. The interannual variability of the Mascarene high is closely related with SST over the southern Indian Ocean and the AAO before 1976,whereas it is closely related with ENSO and the AAO after 197

关 键 词：马斯克林高压 年代际转折 印度洋局地海温 ENSO 南极涛动 

分 类 号：P424[天文地球—大气科学及气象学]