The structure of the Kuroshio west of Kyushu
type: CreativeWork
description: A triangular CTD/ADCP survey was made across the Kuroshio west of Kyushu aboard the R/V Thompson during January, 1986 in order to investigate the water properties and flow field in the Kuroshio. A similar CTD survey was made in July, 1986 aboard the R/V Washington to study the seasonal variability in the Kuroshio. The Kuroshio in this region exhibited a marked seasonal change in its near-surface stratification and water properties. In January, the Kuroshio water was separated from the vertically well-mixed coastal water over the shelf by a strong front located near the shelf break. Horizontal mixing between the Kuroshio and coastal water was observed but was limited near the shelf break. In July, surface coastal water extended far past the shelf break over the Kuroshio region near the surface, and in turn, Kuroshio water intruded onto the shelf near the bottom. Mixing between the Kuroshio and coastal water was found over much of the mid and outer shelf and upper slope, spanning a cross-stream distance of 75 km. In addition, evidence of deep vertical mixing within the Kuroshio itself was found near 32.0°N and 128.2°E, most likely due to internal tidal mixing over the slope. Since Loran C navigation coverage in the study region was poor during the R/V Thompson cruise, a simple averaging technique has been used to convert the ADCP data into an absolute velocity. An error analysis shows that the total error in the absolute ADCP velocity was about ±5 cm/s. The absolute geostrophic velocity using the absolute Doppler velocity at 60 m as the reference velocity was then calculated for the sides of the triangle. The results show that the ADCP velocity shear was in good agreement with the geostrophic shear in the Kuroshio. The Kuroshio flowed through the western section as a coherent current, then split into two streams around a tall seamount as it left through the eastern section. Some recirculation also occurred between the core of the Kuroshio and the slope as well as near…
abstract: A triangular CTD/ADCP survey was made across the Kuroshio west of Kyushu aboard the R/V Thompson during January, 1986 in order to investigate the water properties and flow field in the Kuroshio. A similar CTD survey was made in July, 1986 aboard the R/V Washington to study the seasonal variability in the Kuroshio. The Kuroshio in this region exhibited a marked seasonal change in its near-surface stratification and water properties. In January, the Kuroshio water was separated from the vertically well-mixed coastal water over the shelf by a strong front located near the shelf break. Horizontal mixing between the Kuroshio and coastal water was observed but was limited near the shelf break. In July, surface coastal water extended far past the shelf break over the Kuroshio region near the surface, and in turn, Kuroshio water intruded onto the shelf near the bottom. Mixing between the Kuroshio and coastal water was found over much of the mid and outer shelf and upper slope, spanning a cross-stream distance of 75 km. In addition, evidence of deep vertical mixing within the Kuroshio itself was found near 32.0°N and 128.2°E, most likely due to internal tidal mixing over the slope. Since Loran C navigation coverage in the study region was poor during the R/V Thompson cruise, a simple averaging technique has been used to convert the ADCP data into an absolute velocity. An error analysis shows that the total error in the absolute ADCP velocity was about ±5 cm/s. The absolute geostrophic velocity using the absolute Doppler velocity at 60 m as the reference velocity was then calculated for the sides of the triangle. The results show that the ADCP velocity shear was in good agreement with the geostrophic shear in the Kuroshio. The Kuroshio flowed through the western section as a coherent current, then split into two streams around a tall seamount as it left through the eastern section. Some recirculation also occurred between the core of the Kuroshio and the slope as well as near…
author: Chen, Changsheng
language: en_US
keywords: Ocean currents, Thomas G. Thompson (Ship) Cruise, Thomas Washington (Ship) Cruise
date published: 1989-09
date modified: 2026-07-27T22:05:04Z
provider: Woods Hole Oceanographic Institute
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massachusetts Institute of Technology and Woods Hole Oceanographic Institution

PropertyValue
property ID: Handle
value: https://hdl.handle.net/1912/5393

PropertyValue
property ID: DOI
value: 10.1575/1912/5393