Parameter sensitivity analysis of the short-range prediction of Kuroshio extension transition processes using an optimization approach

Abstract

In this study, the optimization parameter sensitivity analysis (OPSA) method is applied to investigate the sensitivity of the short-range prediction of the Kuroshio extension (KE) transition process to parameter uncertainties as simulated with a reduced-gravity shallow water model. The results show that the uncertainties of the model parameters have important impacts on the short-range predictions of the KE transition processes: the predictions are found to be mainly affected by the uncertainties in the reduced-gravity and interfacial friction coefficients. On the contrary, the prediction is insensitive to the wind stress amplitude and the lateral eddy viscosity coefficient. Furthermore, if the sensitive parameters are more accurately estimated, the prediction will be significantly improved. It is therefore suggested that the OPSA method is a useful tool to assess parameter sensitivity for the prediction of the KE transition processes.