ORCID

Abstract

Globally, the Celtic Sea shelf break is ranked highest as an energetic "hot spot" of tidal energy conversion, therefore making it the most significant contributor to global internal tidal energy flux. In this paper, the three-dimensional dynamics of baroclinic tides in the shelf-slope area of the Celtic Sea was investigated numerically and using observational data collected on the 376th cruise of the RV "RRS Discovery" in June 2012. The time series recorded at a shelf break mooring showed that semidiurnal internal waves were accompanied by packets of internal solitary waves with maximum amplitudes up to 105 m, the largest internal waves ever recorded in the Celtic Sea, and ranking among the largest observed in the global ocean. The observed baroclinic wavefields were replicated numerically using the Massachusetts Institute of Technology general circulation model. A fine-resolution grid with 115 m horizontal and 10 m vertical steps allowed the identification of two classes of short-scale internal waves. The first classification was generated over headlands and resembles spiral-type internal waves that are typical for isolated underwater banks. The second classification, generated within an area of several canyons, revealed properties of quasi-planar internal wave packets. The observed in situ intensification of tidal bottom currents at the shelf break mooring is explained in terms of a tidal beam that was formed over supercritical bottom topography at the mooring location. Key Points Evidence of the largest internal waves ever recorded in the Celtic Sea Numerical replication of the three-dimensional fine structure of baroclinic tide Quasi-plane and spiral-type internal waves at the shelf edge of the Celtic Sea

DOI

10.1002/2013JC009708

Publication Date

2014-05-10

Publication Title

Journal of Geophysical Research: Oceans

Volume

119

Issue

6

ISSN

2169-9275

Keywords

baroclinic tides, Celtic Sea, modeling

First Page

3249

Last Page

3265

Download

Share

COinS