The Volume Transport of the Cheju Warm Current observed in November 2007

Abstract

The volume transport of the Cheju Warm Current (CWC) was measured across the Cheju Strait using acoustic Doppler current profilers in November 2007. Tidal currents were eliminated by 4 times round-trip measurements along a section of 24 nautical miles during 24.83 hours. The transport of the CWC was 0.71 Sv (Sv = 10^6 m^3/s) which was 27% of the average transport of Tsushima Current (2.65 Sv). In April 1995, the transport that was measured in the same way and section was 0.3 Sv which was as small as by 0.4 Sv. This probably due to a seasonal variation of the CWC, such as the Tsushima Current, which shows maximum in the fall and becomes the minimum in winter. The depth of the thermocline was deepened from the coast of Korea toward Cheju-do, and the core of the CWC was in the upper layer of the thermocline. The maximum speed of the current was approximately 0.4 m/s. The velocity distribution observed in the same way in the west of Cheju-do shows that the current core was near the coast. This is an evidence to support the existing concept that the CWC turns around the west of Cheju-do and flows to the Cheju Strait.