大气科学2001，Vol.25Issue(2)：160-172,13.
El Ni o事件发生和消亡中热带太平洋纬向风应力的动力作用*Ⅱ.模式结果分析
Dynamical Role of Zonal Wind Stresses over the Tropical Pacific in the Occurring and Vanishing of El Ni o Part II: Analyses of Modeling Results
摘要
Abstract
A simple tropical numerical ocean model similar to Zebiak′s one is built in order to analyze the dynamical role of zonal wind stresses over the tropical Pacific in the occurring and vanishing of El Ni o events. The model is used to simulate the SSTA variability with time from January of 1971 to August of 1998 by the observed wind stress (FSU) forcing. The results show that the model successfully simulates the variability of SSTA in Ni o3 area with time. The correlation coefficient is 0.9 between observational and modeling SSTA over Ni o3 area. The model can better simulate the horizontal SSTA variability with time during El Ni o events. In order to better understand the mechanism of SSTA spatial distribution with time, as an example, we analyze the SSTA propagating characteristics and its causes in the modeling and observational results over the equatorial Pacific in the ENSO cycle between 1986 and 1989. The model better simulates the observational SSTA propagating characteristics over the equatorial Pacific. That is, the SSTA propagates eastward from the end of 1986 to April of 1987 and westward from June of 1987 to February of 1988. The model results show that the zonal wind stress anomaly over the western and middle equatorial Pacific is very important to the occurring and vanishing of El Ni o events. The wind stress anomaly over the western and middle equatorial Pacific can initiate the eastward Kelvin wave. The eastward Kelvin wave is responsible for the SSTA propagating eastward. When the Kelvin wave reaches the east boundary, the westward propagating Rossby waves are initiated because of east boundary reflection. The westward propagating Rossby waves are responsible for SSTA propagating westward over the equatorial eastern Pacific. The propagating eastward Kelvin wave and the propagating westward Rossby waves from east boundary reflection are responsible for the second peak of SSTA in El Ni o events over the east equatorial Pacific.关键词
ElNio事件/Rossby波/Kelvin波分类
天文与地球科学引用本文复制引用
严邦良,黄荣辉,张人禾..El Ni o事件发生和消亡中热带太平洋纬向风应力的动力作用*Ⅱ.模式结果分析[J].大气科学,2001,25(2):160-172,13.
