【作者】 秦育婧；

【导师】 王盘兴； 管兆勇；

【作者基本信息】 南京信息工程大学 ， 气象学， 2009， 博士

【摘要】 本文用子午面上的质量流函数ψ定量地表示哈德莱环流（H.C.）,论证了H.C.是全（局）域气候子午面环流的主要构成部分,比较了ERA-40、NCEP/NCAR两种再分析资料（E、N）对H.C.研究的适用性,分析了全（局）域H.C.的气候及异常特征,初步探讨了它们的成因,初步分析了东亚季风区H.C.与我国气候异常的关系。得到以下主要结论:1)通过比较全（局）域气候H.C.质量流函数（?）（（?）₁）给出的质量垂直输送强度（?）(（?）_ψ1)与由子午面实际垂直风分量ω决定的实际质量垂直输送强度（?）（（?）₁）,定量论证了气候全（局）域H.C.是热带子午面气候环流的主要构成部分。2)通过气候射出长波辐射（OLR）极小值所在纬度与ERA-40、NCEP/NCAR资料气候H.C.公共上升支中心所在纬度的比较,论证了ERA-40资料较NCEP/NCAR资料在H.C.的分析中更为合理。3)全域H.C.公共上升支强度演变曲线ψ_c与质量流函数异常场ψ′EOF分析第一特征向量X₁时间系数曲线T₁强正相关。它们的年际变化分量与ENSO显著正相关;各季中月的X₁表明,在El Ni（?）o事件中出现一个中心位于赤道附近的异常经圈环流,它使1、7月冬半球H.C.中心及公共上升支加强并向赤道靠近。该异常经圈坏流由El Ni（?）o事件时纬向平均SST′（φ）在赤道附近出现的显著正异常强迫产生。4)东亚季风区（EA）、东太平洋区（EP）气候H.C.存在明显差异,且不同于全域气候H.C.。EA区H.C.的控制范围较宽,基本在40°S～40°N之间,7月甚至能到60°N以北,4、7月H.C.公共上升支宽而强。EP区H.C.的活动范围较窄,基本在20°S～30°N之间。EA区H.C.季节变化较EP区明显。上述H.C.的区域差异,既与所在经度区域热带洋面的强烈冷暖对比有关,也与海陆分布及地形的巨大差异有关。5)东亚季风区（EA）和东太平洋区（EP）H.C.异常有明显的相关关系。ElNi（?）o事件时,EA区H.C.减弱（7月除外）,EP区H.C.增强。这种相关关系与ENSO事件及赤道异常西（东）风密不可分。7月EA区H.C.的异常及其与EP区H.C.异常和ENSO事件的关系与1、4、10月存在明显差异。6)4、7月东亚季风区H.C.存在热带支和副热带支两个上升中心,分别与热带辐合带（季风槽）和副热带辐合带（梅雨锋）对应;因此其异常与南海季风及副热带季风异常关系密切。春季H.C.热带支北移时间偏早,10～20°N上升流出现异常偏强,南海季风爆发较早。夏季,强的副热带支上升流与江淮流域涝年对应;反之亦然。更多还原

【Abstract】 This paper demonstrates the rationality of the mass stream function(MSF) for describing Hadley circulation(H.C.).Climate state of two H.C.from ERA-40 and NCEP/NCAR reanalysis dataset are compared.Climate and anomalous state of global H.C.,as well as regional H.C.in the East Asian monsoon region and the East Pacific, and their link with ENSO events and climate anomalies in China are investigated.By the following major conclusions:1) By comparing the vertical air mass flux intensity derived from global (regional) zonally averaged air mass stream function and the actual vertical air mass flux intensity calculated by vertical velocity on the meridian plane,we demonstrated that climatological global(regional) H.C.is the main part of actual vertical transportation on the tropical meridian plane.2) Through comparing the latitudes of minimum variables of climatological OLR with the latitudes of ascending branch center derived from ERA40 data as well as NCEP/NCAR data,it is verified that using ERA40 data for H.C.analysis is more reasonable than NCEP/NCAR data.3) The time-evolving intensity of the ascending branch of global H.C.ψ.has positive relationship with PC1.And their inter-annual variations are significantly positive related to ENSO.During the E1 Nino events,an anomalous meridional circulation is centered in the vicinity of the tropics,which makes the center of the winter hemisphere and the ascending branch more intense and move toward the Tropics.And the anomalous meridional circulation is triggered by the positive anomalous forcing of zonally averaged SST’(φ) profile appeared in the vicinity of the tropics during the E1 Nino events.4) Features of H.C.in the East Asian monsoon region(EA),the East Pacific region(EP) and global differ outstandingly from each other.The active region of H.C. in EA is wider which is basically between 40°S and 40°N.Moreover,it stretches to the north of 60°N in July.And the ascending branch of H.C.is wide and intense in April and July.Comparatively,the active region of H.C.in EP is narrower which is between 20°S and 30°N.The seasonal variation of H.C.in the two regions is different obviously.H.C.has apparent(obscure) seasonal variation in EA(EP).The differences of H.C.in the above regions are related to the thermal contrast of the tropical SST and the land-sea contrast along with the enormous differences of topography. 5) The anomalies of H.C.in the two regions are significantly correlated.During El Nino periods,the intensity of H.C.in EA is weakened while that in EP is strengthened(except in July).This relationship is related to the ENSO events and zonal wind anomalies near the equator.In July,the relationships of anomalous H.C.in EA with that in EP as well as the ENSO events are rather special.6) There are two ascending branches for the EA H.C.in both April and July, which are connected with ITCZ(monsoon trough) and subtropical convergence zone(Mei-yu front) respectively.Therefore anomalous H.C.is closely related with the anomalies of South China Sea monsoon and subtropical monsoon.In spring,the tropical H.C.branch moves northward earlier,the ascending branch in 10～20°N is anomalously strong and the South China Sea monsoon breaks out earlier.In summer, the intense subtropical ascending branch is related with surplus rainfall in the Yangtze-Huaihe River Valley and vice versa.更多还原