동해통과류의 장기 변화 및 동해 온나화에의 영향

Abstract

The prominent long-term change of the East Sea (Japan Sea) is the deep water warming and the depletion of oxygen in the deep layer during the last 40 years. The cause of this phenonmena explained mainly by the slow down of the deep convection in the northern region influenced by the global warming. A distinguished feature of the East Sea is the upper layer flow through the three major straits connected to the Pacific Ocean. Generally, East Sea Throughflow (EST) supplies the warm water through the Korea Strait and drains relatively cold water through the Tsugaru and the Soya Straits. In this study, the role of the EST transport variation on the East Sea warming has been investigated. To understand the EST transport variability, monthly mean EST transport time series extracted from the Simple Ocean Data Assimilation Ver. 1.4.2 data during the period of 1958 to 2001. It shows that winter time transport anomaly seems to have overall increasing trend with PDO(Pacific Decaldal Oscillation) like flucuation. The relation between the EST transport anomaly and the local or remoter wind stress anomly has been studied. We have also carried out a numerical 3-D regional model to understand the East Sea response to the long-term EST transport change. Though the EST confined in the upper layer, it is interesting to note the EST can affect on the meridional overturning strength by way of changing the heat transport amount to the convection favorable region. Possible influences of the EST tranpsport variability on the East Sea warming are discussed.