Volume transports through the main straits of the East China Sea based on HYCOM reanalysis data

Abstract

Volume transports through the main straits of the East China Sea and the inter-annual variations are determined based on HYCOM reanalysis data in the period from 1993 to 2012. The annual mean transports through Taiwan Strait (TS) and Tsushima Strait (TUS) are approximately 1.24Sv (1Sv=106m3/s), and 2.41Sv, respectively. This suggests that the onshore intrusion of Kuroshio water crossing the shelf break of the East China Sea is around 1.17Sv. These estimations are consistent with the previous studies. Furthermore, the volume transports of other channels connecting the East China Sea with the open ocean also have been checked, which are 27.78Sv, 28.55Sv and 1.93Sv through East of Taiwan (TE), Tokara-Osumi Strait (TOS) and the Ryukyu Islands chain (RK), respectively. The Kuroshio transport of HYCOM reanalysis data is larger than the climatological value pointed out from the earlier studies. However, it is much closer to the new analysis value (28.1Sv) based on the observation of Japan Meteorological Agency during the period between 2003 and 2006. The possible reasons also have been addressed. The long-term trend suggests that the transports of TS and TUS have been increased slightly, while those of ET and TOS have been decreased.