케라마갭 overflow에 대한 지형조절의 영향

Abstract

The Kerama Gap is the deepest ventilation connecting the Okinawa Trough in the East China Sea to the Philippine Sea (Fig. a). This gap has proved to be of considerable importance for the deepwater exchange of the Okinawa Trough. We performed observations to examine the temporal and spatial velocity variations below the thermocline in the Kerama Gap, between June 2009 and June 2011. The observed results revealed that a steady deep flow (> 10cm/s) into the Okinawa Trough is clearly present on the norther slope of Kerama Gap, and its volume transport is about 0.6 Sv. This paper tries to point out that the theory of topographic control allows new physical insight into the deep overflow through the gap. We use data in the period 2009/06 - 2011/06 from moored current-meters, daily nowcasting outputs from GOFS V3.0, which is based on the 1/12° HYCOM and the NCODA system, and the ARGO real-time quality controlled float data. Annual mean deep overflow structures in the period 2010/06 - 2011/06 are explained in this abstract.The velocity section across the gap based on the model outputs (Fig. b) indicates a steady deep flow into the Okinawa Trough on the northern slope, similar to that observed. Another interesting characteristic is a strong bottom-intensified inflow (24 cm/s) on the gap sill. We can also find a similar structure to the modeled bottom-intensified inflow in observational dataormed observations to examine the temporal and spatial velocity variations below the thermocline in the Kerama Gap, between June 2009 and June 2011. The observed results revealed that a steady deep flow (> 10cm/s) into the Okinawa Trough is clearly present on the norther slope of Kerama Gap, and its volume transport is about 0.6 Sv. This paper tries to point out that the theory of topographic control allows new physical insight into the deep overflow through the gap.