The SST-Wind Coupling Pattern in the East China Sea Based on a Regional Coupled Ocean-Atmosphere Model

摘要

To study the interaction between sea surface temperature (SST) and surface wind in the East China Sea (ECS), the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modelling system is used to downscale a global atmospheric reanalysis product over the study area in 2013. A singular value decomposition (SVD) method is applied to SST and surface wind speed to study their coupling relationship in the ECS. The heterogeneous correlation map indicates that the surface wind has a negative correlation with the SST, especially in the Kuroshio Current. From lead-lag correlations between the first principal component of SST and surface wind SVD (filtered using a Lanczos high-pass filter with a 90-day cut-off), a correlation of about 0.1 is found at lag -6, and a negative correlation of about -0.3 is also found around lag 1. The results indicate a negative feedback between SST and wind fluctuations at short time-scales. Air-sea heat fluxes contribute little to the SST variability in the ECS section of the Kuroshio and the analysis of the mixed-layer heat budget shows that the contribution of horizontal advection is dominant in determining the intraseasonal SST signals.