IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Print this page

First Evidence of coherent bands of strong turbulent layers associated with high-wavenumber internal-wave shear in the upstream Kuroshio
Nagai, T.; Hasegawa, D.; Tanaka, T.; Nakamura, H.; Tsutsumi, E.; Inoue, R.; Yamashiro, T. (2017). First Evidence of coherent bands of strong turbulent layers associated with high-wavenumber internal-wave shear in the upstream Kuroshio. NPG Scientific Reports 7(1): 14 pp. https://hdl.handle.net/10.1038/s41598-017-15167-1
In: Scientific Reports (Nature Publishing Group). Nature Publishing Group: London. ISSN 2045-2322; e-ISSN 2045-2322, more
Peer reviewed article  

Available in  Authors 

Authors  Top 
  • Nagai, T.
  • Hasegawa, D.
  • Tanaka, T.
  • Nakamura, H.
  • Tsutsumi, E.
  • Inoue, R.
  • Yamashiro, T.

Abstract
    The upstream Kuroshio flows through Okinawa Trough and the Tokara island chain, the region near the continental shelf of the East China Sea and shallow seamounts, where the Kuroshio can induce strong mixing over the shallow topography. Also, tidal currents over the rough topography may produce internal tides, and associated turbulence. The previous observations show energetic high vertical wavenumber near-inertial wave shear in the Kuroshio thermocline, which implies strong turbulent mixing. However, direct turbulence measurements in this region are very scarce. Using high lateral resolution (1-2 km) direct turbulence measurements, we show here, for the first time, that strong turbulent layers form spatially coherent banded structures with lateral scales of >O(10 km), associated with bands of near-inertial wave/diurnal internal tide shear of high vertical wavenumber in the upstream Kuroshio. The turbulent kinetic energy dissipation rates within these turbulent layers are >O(10-7 W kg(-1)), and estimated vertical eddy diffusivity shows >O(10(-4) m(2) s(-1)) on average. These results suggest that the high vertical wavenumber near-inertial waves propagating in the upstream Kuroshio could have large impacts on the watermass modifications, momentum mixing, nutrient supply, and associated biogeochemical responses in its downstream.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors