南海-西北太平洋季风槽强度变化的特征及其与热带气旋活动的关系  

ON RELATIONSHIP BETWEEN VARIATION OF THE MONSOON TROUGH INTENSITY IN THE SOUTH CHINA SEA-WESTERN NORTH PACIFIC AND TROPICAL CYCLONE ACTIVITIES

作　　者：高建芸[1] 余锦华[2] 张秀芝[3] 张容焱[1] 

机构地区：[1]福建省气象科学研究所,福建福州350001 [2]江苏省气象灾害重点实验室/南京信息工程大学,江苏南京210044 [3]国家气候中心,北京100081

出　　处：《热带气象学报》2011年第1期63-73,共11页Journal of Tropical Meteorology

基　　金：江苏省气象灾害重点实验室开放课题资助(KLME0708);国家自然科学基金项目(90915002;40775047;40775058);福建省科技厅青年人才项目(2007F3019)共同资助

摘　　要：利用1979—2005年NCEP/DOE AMIP-Ⅱ再分析逐日平均资料,根据西北太平洋季风槽的特点,研制了能较好表征季风槽活动的强度指数和位置指数,并分三段描述不同区域季风槽的活动特征及其对生成于南海-西北太平洋季风槽的热带气旋(MTTC)活动的影响,结果表明:(1)季风槽强度指数和位置指数呈正相关关系,季风槽强度越强,其位置越偏北。(2)季风槽强度存在明显的年际变化,1994年前以4～5年的变化周期较为显著,1994年后2～3年的周期较明显。(3)不同区域季风槽强度的影响因子不同。前期海温场的异常将导致大气环流异常,致使不同区域的季风槽强度异常。(4)季风槽强度与MTTC频数异常密切相关,3个不同区域的季风槽以南海季风槽强度与MTTC频数异常的关系最为密切。MTTC异常偏少年大多出现在季风槽总体偏弱,各区域季风槽也偏弱的年份;MTTC异常偏多年可能出现在季风槽偏强的年份,也可能出现在季风槽总体偏弱但南海季风槽偏强的年份,且后者出现的概率更大一些。(5)季风槽强度的季节内变化能为TC的生成和发展提供有利条件,季风槽同时处于30～60天振荡和准双周10～20天振荡的活跃期时,有利于MTTC的生成。According to the characteristic of Monsoon Trough in the Western North Pacific,the intensity index and position index have been established to describe the Monsoon Trough activity,followed by analysis on behaviors of monsoon trough in the three different regions and their impacts on tropical cyclones generated in monsoon trough（hereinafter MTTC）,based on the dail average of the NCEP/DOE AMIP-II re-analysis data fro 1979 to 2005.Following conclusions are obtained：（1） The established monsoon trough intensity index and the position index have a positive correlation,indicating that stronger monsoon trough intensity corresponds to more northward position.（2） Monsoon trough intensity exhibits significant inter-annual variation,with obvious periods of 4～5 years prior to 1994 and 2～3 years afterwards.（3） The factors of impacts on monsoon trough intensity are different in different areas.The precedent SST anomaly aill result in anomalous atmospheric circulation,leading to anomaly of monsoon trough intensities in different areas.（4） The intensity of the monsoon trough is closely correlated with the frequency of MTTC,in particular,among the monsoon troughs in three different areas,that in the SCS is most closely correlated to the anomaly of MTTC frequency.Negative anomaly of MTTC frequency mainly occurs in the years when the monsoon troughs and those in different areas are overall weak,while positive anomaly of MTTC frequency might happen in the years with strong monsoon trough intensity,and more probably when the monsoon troughs are overall weak but strong in the the South China Sea region.（5） The interseasonal variation on intensities of monsoon troughs provides favorable conditions for TC generation and development.That the monsoon trough is in the active periods of both quasi-biweekly 10～20 day and 30～60 day oscillations is a favorable for MTTC occurrence.

关 键 词：南海-西北太平洋季风槽 强度变化 热带气旋 

分 类 号：P444[天文地球—大气科学及气象学]