Inverse Determination of Surface Heat Flux over the Yellow Sea in Winter 1986 from Sea Surface Temperature Data

Abstract

An assimilation of routine sea surface temperature observations is conducted to estimate the sea surface heat flux in the Yellow Sea during the winter of 1986. Ten-day mean SST compilations, published by the Japan Meteorological Agency, are used. The time window is from 0000 Japan Local Time (JLT) 21 January to 0000 JLT 21 February 1986. Because there are only three frames of the observed temperature available for the time window, only a steady-state distribution of the heat flux is determined. A tonguelike feature of the optimized heat flux distribution is consistent with the warm SST anomaly at the center of the Yellow Sea trough. The optimized heat flux generates improved simulation of the cooling trend of the temperature time series. The variational method is the assimilation procedure employed. The developed scheme is able to optimize simultaneously the initial temperature condition and the sea surface heat flux without a priori knowledge of either. A coarse-resolution Hessian is used to evaluate errors of the assimilation.