Marine & Environmental Sciences Faculty Articles

Observation of Wave-Enhanced Turbulence in the Near-Surface Layer of the Ocean During TOGA COARE

Document Type

Article

Publication Date

3-2003

Publication Title

Deep Sea Research Part I: Oceanographic Research Papers

Keywords

Turbulence, Wave breaking, Surface roughness, Dissipation rate

ISSN

0967-0637

Volume

50

Issue/No.

3

First Page

371

Last Page

395

Abstract

Dissipation rate statistics in the near-surface layer of the ocean were obtained during the month-long COARE Enhanced Monitoring cruise with a microstructure sensor system mounted on the bow of the research vessel. The vibration contamination was cancelled with the Wiener filter. The experimental technique provides an effective separation between surface waves and turbulence, using the difference in spatial scales of the energy-containing surface waves and small-scale turbulence. The data are interpreted in the coordinate system fixed to the ocean surface. Under moderate and high wind-speed conditions, we observed the average dissipation rate of the turbulent kinetic energy in the upper few meters of the ocean to be 3–20 times larger than the logarithmic layer prediction. The Craig and Banner (J. Phys. Oceanogr. 24 (1994) 2546) model of wave-enhanced turbulence with the surface roughness length from the water side z0 parameterized according to the Terray et al. (J. Phys. Oceanogr. 26 (1996) 792) formula z0=cHs provides a reasonable fit to the experimental dissipation profile, where z is the depth (defined here as the distance to the ocean surface), c≈0.6, and Hs is the significant wave height. In the wave-stirred layer, however, the average dissipation profile deviates from the model (supposedly because of extensive removing of the bubble-disturbed areas close to the ocean surface). Though the scatter of individual experimental dissipation rates (10-min averages) is significant, their statistics are consistent with the Kolmogorov's concept of intermittent turbulence and with previous studies of turbulence in the upper ocean mixed layer.

Comments

©2003 Elsevier Science Ltd. All rights reserved.

Additional Comments

NSF grant #s: OCE-9525986, OCE-9730643

Additional Files
deep_sea_research_i.png (69 kB)

ORCID ID

0000-0001-6519-1547

DOI

10.1016/S0967-0637(03)00004-9

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