利用1979—2009年的NECP资料、Hadley海温月平均资料和CMAP降水资料,采用Kao and Yu(2009)的方法定义了夏季EP型ENSO指数EPI,用合成分析的方法分析了东部型ENSO与海洋性大陆降水的关系。结果表明:EPI与MC(Maritime Continent,海洋性大陆...利用1979—2009年的NECP资料、Hadley海温月平均资料和CMAP降水资料,采用Kao and Yu(2009)的方法定义了夏季EP型ENSO指数EPI,用合成分析的方法分析了东部型ENSO与海洋性大陆降水的关系。结果表明:EPI与MC(Maritime Continent,海洋性大陆)区域降水变化间存在非常弱的负相关。造成这一弱相关的原因是EPI与MC区域降水在某些年份存在同号变化。在剔除Nio4信号后,海洋性大陆区域降水序列与EPI与存在着同号和反号两种关系。反号关系是通常所认为的,当经典的El Nio(La Nia)发生时MC区域降水出现显著地减少(增多)。此时,沿赤道的异常Walker环流建立了EP型ENSO与MC区域气候间的直接联系。而在同号关系时,菲律宾以东异常加热和SPCZ区域异常冷却引起的西北—东南走向的垂直环流圈削弱了MC区域与赤道东太平洋之间的异常Walker环流所建立的直接联系,或者说,赤道东太平洋区域SSTA与MC区域降水异常的形成是通过SPCZ区域SST的反号异常而产生间接联系的。这种机制的揭示为深刻认识ENSO影响海洋性大陆区域甚至东亚地区气候变动的联系提供了新的线索。展开更多
Some recent studies presented two existing types of ENSO events, one is the Eastern-Pacific(EP) type and the other the Central-Pacific(CP) type. This study examined the monitoring ability of several current operationa...Some recent studies presented two existing types of ENSO events, one is the Eastern-Pacific(EP) type and the other the Central-Pacific(CP) type. This study examined the monitoring ability of several current operational ENSO indices. The results indicated that a single index could not distinguish the EP and CP in the historical ENSO events during 1950-2009. The Nio 3 index may only be suitable for monitoring the EP-type ENSO, while the Nio 4 index works only for the CP-type ENSO. In order to capture the occurrence of ENSO events and distinguish the type, we considered a new monitoring index group using Nio 3 and Nio 4 indices. Further analysis confirmed that this index group can monitor different types of historical ENSO events with different spatial distribution of sea surface temperature. It has a good performance in determining the characteristics of the ENSO events, including peak intensity, onset,decay, and mature phase.展开更多
针对1950—2009年的东部型(EP)和中部型(CP)ENSO事件,比较了目前国际上常用的ENSO监测指数对它们的监测能力。结果表明:单一的指数无法同时区分EP和CP型ENSO事件,其中Ni o 3指数只能有效识别EP型ENSO事件,而Ni o 4指数则对CP型事件具有...针对1950—2009年的东部型(EP)和中部型(CP)ENSO事件,比较了目前国际上常用的ENSO监测指数对它们的监测能力。结果表明:单一的指数无法同时区分EP和CP型ENSO事件,其中Ni o 3指数只能有效识别EP型ENSO事件,而Ni o 4指数则对CP型事件具有较强的监测能力。据此提出同时以Ni o 3和Ni o 4指数构建指数组的形式来监测不同类型的ENSO事件,结果表明,该指标组能够较全面监测历史上发生的不同分布类型ENSO事件,且能准确判定事件的峰值强度、起止时间和成熟期等其他特征。展开更多
基金The Definition of El Nio/La Nia Episodes,a National Standard ProjectSpecialized Project for Public Welfare Industries(GYHY201406018,GYHY200806009)+2 种基金Program 973(2012CB955901)National Science and Technology Support Program(2009BAC51B05)National Youth Foundation for Natural Science(41005038)
文摘Some recent studies presented two existing types of ENSO events, one is the Eastern-Pacific(EP) type and the other the Central-Pacific(CP) type. This study examined the monitoring ability of several current operational ENSO indices. The results indicated that a single index could not distinguish the EP and CP in the historical ENSO events during 1950-2009. The Nio 3 index may only be suitable for monitoring the EP-type ENSO, while the Nio 4 index works only for the CP-type ENSO. In order to capture the occurrence of ENSO events and distinguish the type, we considered a new monitoring index group using Nio 3 and Nio 4 indices. Further analysis confirmed that this index group can monitor different types of historical ENSO events with different spatial distribution of sea surface temperature. It has a good performance in determining the characteristics of the ENSO events, including peak intensity, onset,decay, and mature phase.
文摘针对1950—2009年的东部型(EP)和中部型(CP)ENSO事件,比较了目前国际上常用的ENSO监测指数对它们的监测能力。结果表明:单一的指数无法同时区分EP和CP型ENSO事件,其中Ni o 3指数只能有效识别EP型ENSO事件,而Ni o 4指数则对CP型事件具有较强的监测能力。据此提出同时以Ni o 3和Ni o 4指数构建指数组的形式来监测不同类型的ENSO事件,结果表明,该指标组能够较全面监测历史上发生的不同分布类型ENSO事件,且能准确判定事件的峰值强度、起止时间和成熟期等其他特征。
