Flow through the Ulleung Interplain Gap

Abstract

The paper describes results of long-term deep current measurements in the Ulleung Interplain Gap (UIG) which is a major conduit for deep water exchanges between the Japan and Ulleung Basins (UB). Deep currents in the central UIG below 400 m are persistently into the UB with a mean speed of 1~2 cm/s that evidences the deep inflow from the Japan Basin to the UB. Bottom intensification and mesoscale current fluctuations with periods of 20~50 days characterize the observed deep flow. Although an accurate estimation of the influx of deep water is hampered by a limited sampling, the observed long-term currents suggest a net influx into the UB that could result in a substantial deep diapycnal mixing in the UB and drive the observed mean deep cyclonic circulation of the UB.