서태평양에서 온난역의 해수면 온도 증가에 따른 바람 응력의 변동

Abstract

The western Pacific warm pool is conventionally defined as an area where SST is higher than 28C. SST values exhibits a simple thermodynamic energy balance between evaporative heat loss and radiative energy input. Ocean dynamics in the warm-pool act on the eastward expansion of warm SST through equatorial wave-induced zonal advection, and it also plays a key role to maintain the warm-pool SST through the poleward Ekman transport at the surface layer. The strong east-west migration of the warm-pool in the equatorial western Pacific is closely linked to surface current variation driven by the ENSO-related surface winds. Anomalous easterly (westerly) trade winds force the thermocline depth. The trade winds also induce the Ekman upwelling associated the Coriolis effects, which brings the cold water to surface layer in the eastern Pacific. Recent studies have suggested that the warmpool SST is increasing over the last century. Warmer SST may change surface winds, which in turn change ocean currents connecting the western tropical Pacific Ocean with the eastern tropical Pacific Ocean. In this study, we examine long-term changes in the center of the wind stress with the SST increase in the warm-pool region for the period 1950-2011. The SSTs are obtained from the Hadley Centre SST dataset, ERSST (Extended Reconstructed SST v3b), SODA (Simple Ocean Data Assimilation, version 2.2.4) data set.pool act on the eastward expansion of warm SST through equatorial wave-induced zonal advection, and it also plays a key role to maintain the warm-pool SST through the poleward Ekman transport at the surface layer. The strong east-west migration of the warm-pool in the equatorial western Pacific is closely linked to surface current variation driven by the ENSO-related surface winds. Anomalous easterly (westerly) trade winds force the thermocline depth. The trade winds also induce the Ekman upwelling associated the Coriolis effects, which brings the cold water to surface layer in the eastern Pacific. Recent studies have suggested that the warmpool SST is increasing over the last century. Warmer SST may change surface winds, which in turn change ocean currents connecting the western tropical Pacific Ocean with the eastern tropical Pacific Ocean. In this study, we examine long-term changes in the center of the wind stress with the SST increase in the warm-pool region for the period 1950-2011. The SSTs are obtained from the Hadley Centre SST dataset, ERSST (Extended Reconstructed SST v3b), SODA (Simple Ocean Data Assimilation, version 2.2.4) data set.