Sensitivity of the Equatorial Air-Sea Coupled System to the Zonal Phase Difference between SST and Wind Stress

作     者：Soon-Il An In-Sik Kang 

作者机构：International Pacific Research CenterSOESTUniversity of Hawaii at ManoaHonoluluHawaii 96822USA School of Earth Environment SciencesSeoul National UniversitySeoul151-742Korea 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2001年第18卷第2期

页      面：155-165页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：Soon-Il An was supported by Frontier Research System for Global Change through its sponsorship of International Pacific Research Center In-Sik Kang was supported by the Brain Korea 21 Project the SRC project of Korean Science and Technology Foundation 

主　　题：Air-sea coupled system El Niño Slow mode 

摘      要：An eigen analysis of the equatorial air—sea coupled model is carried out to understand the mechanism of the slowly varying mode for various zonal phase differences between SST and wind stress. The frequency and growth rate of the slow mode highly depend on the zonal phase difference between SST and wind stress anomalies and the wave scale. For ultra—long waves longer than 20,000 km, the system propagates westward regardless of the position of wind stress. However, for the long waves observed in the Pacific, the slow mode tends to propagate eastward when the SST and wind stress anomalies are close to each other (within a quadrature phase relationship). On the other hand, when the wind stress is located far away from SST, the slow mode tends to propagate westward. The coupled system produces the unstable modes when the westerly (easterly) wind stress is located in the west of warm (cold) SST. It is noted that for the Pacific basin scale, the eastward propagating unstable waves can be produced when the wind stress is located to the west of SST with a few thousand kilometer distance. Also examined in the present study is the relative role of the thermocline displacement and zonal advection effects in determining the propagation and instability of the coupled system. Key words Air-sea coupled system - El Ni?o - Slow mode Soon-Il An was supported by Frontier Research System for Global Change through its sponsorship of International Pacific Research Center, and In-Sik Kang was supported by the Brain Korea 21 Project and the SRC project of Korean Science and Technology Foundation. The authors thank Diane Henderson for her careful reading and editing of the manuscript. SOEST Contribution Number is 5285. IPRC contribution number is IPRC-63.