赤道太平洋次表层海温模态在ENSO循环中的作用  

ROLE OF EQUATORIAL PACIFIC OCEAN SUBSURFACE OCEANIC TEMPERATURE MODE IN ENSO CYCLE

作　　者：刘正奇[1] 刘玉国[1] 哈瑶[2] 张桁正[1] 

机构地区：[1]南海舰队海洋水文气象中心,广东湛江524001 [2]解放军理工大学气象海洋学院,江苏南京211101

出　　处：《热带气象学报》2013年第2期255-261,共7页Journal of Tropical Meteorology

基　　金：国家重点基础研究计划发展项目(2013CB956203)资助

摘　　要：利用美国马里兰大学海洋同化月平均再分析资料(SODA),分离出赤道太平洋次表层海温异常(SOTA)的年际变率和年代际变率,利用经验正交分解(EOF)方法分别得到SOTA年际变率和年代际变率的第一模态和第二模态,重点分析了第二模态在ENSO循环中的作用。结果表明,赤道太平洋年际变率和年代际变率的第一模态为偶极子分布,此分布型是ENSO循环冷暖位相在次表层的同时表现。第二模态以次表层范围较广的海温异常趋势一致分布为显著特征,该模态是ENSO循环演变过程的重要环节。第二模态时间系数与Ni o-3.4指数具有较好的超前相关性,可作为ENSO事件的预测前兆信号,合成和个例分析验证了这一次表层信号的预测指示作用。Based on the simple ocean data assimilation （SODA） reanalysis dataset from University of Maryland and with the method of Empirical Orthogonal Functions （EOF）, the characteristics of interannual and interdecadal variability are captured. The first and second modes of the equatorial Pacific subsurface ocean temperature anomaly （SOTA） in the interannual and interdecadal variability are found, respectively, and the second mode in ENSO cycle is discussed. The results show that the first mode of SOTA＇s interannual and interdecadal variability has a dipole pattern, indicating that the warm and cold phases simultaneously appear in the equatorial subsurface Pacific. The second mode shows coherent large-scale sea temperature anomaly in the equatorial subsurface Pacific, which prominently influences the phase evolution of ENSO cycle. The time series of the second mode has a lead correlation with the Nifio-3.4 index, which makes a precursory prediction signal for ENSO. The function of the prediction factor in SOTA is verified by the composite and case analysises.

关 键 词：ENSO循环 次表层海温异常模态 预测信号 赤道太平洋 

分 类 号：P731.11[天文地球—海洋科学]