太阳活动对NAO与冬季中东急流轴线位置之间关系的调制作用
投稿时间: 2016-04-03  最后修改时间: 2016-05-15  点此下载全文
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吴玲玲 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044;南京铁道职业技术学院 社会科学教学部, 江苏 南京 210031;南京信息工程大学 数学与统计学院, 江苏 南京 210044  
张建伟 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044;南京信息工程大学 数学与统计学院, 江苏 南京 210044  
邓伟涛 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044 nimmjy@nuist.edu.cn 
赵鹤 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044  
陈宇杨 南京信息工程大学 气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏 南京 210044  
基金项目:国家自然科学基金资助项目(41205035;41575057;41575085;41575102);江苏省普通高校研究生科研创新计划(CXZZ11_0627);江苏高校优势学科建设工程资助项目(PAPD);江苏省大学生实践创新训练计划项目(201410300074X;201610300151)
中文摘要:利用NCEP/NCAR大气环流再分析资料和NOAA提供的太阳黑子资料,讨论了冬季中东急流年际变化特征,并探讨了太阳活动对北大西洋涛动(North Atlantic Oscillation,NAO)与冬季中东急流轴线位置之间关系的调制作用。结果表明:冬季中东急流的轴线位置表现出显著的年际变化特征,在空间上主要表现了中东急流东西两侧轴线南北移动呈反向变化(Middle East Jet Axis shift east-west Out-phase,MEJAO)型和中东急流轴线南北移动呈整体一致的变化特征(Middle East Jet Axis shift In-phase,MEJAI)型。另外,在太阳活动强时期,NAO(North Atlantic Oscillation,北大西洋涛动)的空间结构更靠近北大西洋东侧的大陆上,欧洲大陆北侧与地中海地区出现相反的SLP(Sea Level Pressure,海平面气压)异常,通过Ekman抽吸作用形成次级环流,在对流层高层地中海地区易出现辐合异常,并激发Rossby波波列,在伊朗高原上空会形成位势高度异常,从而中东急流东部轴线南北侧西风呈相反的变化。同时,在对流层高层欧洲大陆南侧形成的位势高度异常,也会使得中东急流西部轴线北侧西风出现异常。中东急流东、西部西风异常的空间结构呈反相变化,即出现了MEJAO型。而在太阳活动弱时期,NAO的空间结构主要局限在北大西洋地区,不易形成地中海辐合异常,NAO与MEJAO型的关系不密切。因此,太阳活动对NAO与MEJAO型之间的关系存在着调制作用。
中文关键词:中东急流  轴线位置  太阳活动  调制
 
Solar cycle modulation on the relationship between North Atlantic Oscillation and Middle East subtropical westerly jet stream axis shift
Abstract:Afro-Asian subtropical westerly jet stream in the Eastern Hemisphere is formed from West Africa through the Arabian Peninsula,South Asia and East Asia to the North Pacific.Currently,most studies on the Afro-Asian subtropical westerly jet streams have focused on the East Asian westerly jet stream,which lies in the eastern part of Eurasia,but less attention has been paid to the Middle East westerly jet stream(MEJ),which situates in the western part of Eurasia.The MEJ is an important circulation system that affects the climate of Northern Hemisphere’s mid-latitude regions and is closely related to the climate of China.Here,by means of National Centers for Environmental Prediction/National Center for Atmospheric Research monthly reanalysis data,and sunspot data provided by National Oceanic and Atmospheric Administration,the inter-annual variation characteristics of wintertime MEJ and solar cycle modulation of the relationship between North Atlantic Oscillation(NAO) and MEJ axis south-north shift are studied.The results show that wintertime MEJ axis north-south shift has obvious inter-annual variation feature.The spatial variation of MEJ manifests axis shift east-west out-phase(MEJAO) pattern and axis shift in-phase(MEJAI) pattern.Furthermore,solar activity has obvious 11-year period.In the high solar activity cases,the location of NAO’s spatial structure is more close to the continent that is situated near the east of North Atlantic,and there are opposite sea level pressure(SLP) anomalies at the north of Europe and Mediterranean Sea.Through Ekman pumping,these anomalous SLP can bring secondary circulation and Mediterranean convergence(MC) anomaly at the high level of troposphere.By Rossby wave train excited by anomalous MC,there are geopotential height anomalies in Iran Plateau at the high level of troposphere,which can lead to westerly opposite changes between south and north sides of eastern MEJ axis.In addition,there are geopotential height anomalies in southern Europe at the high level of troposphere,which can bring to westerly anomalies at north side of western MEJ axis.The distribution of westerly anomalies between south and north sides of the eastern MEJ axis is opposite to that of western MEJ axis,which is manifested MEJAO pattern.In the low solar activity cases,the spatial structure of NAO is located at the Atlantic,which is difficult to form MC anomaly.The relationship between NAO and MEJAO pattern is not obvious.Therefore,there is solar cycle modulation of the relationship between NAO and MEJ axis shift.
keywords:Middle East subtropical westerly jet stream  axis shift  solar activity  modulation
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