Short-Period Internal Waves under an Ice Cover in Van Mijen Fjord, Svalbard

E G Morozov,A V Marchenko,A S Shestov,S V Muzylev

doi:10.1155/2011/573269

Abstract

Temperature and velocity fluctuations measured in Van Mijen Fjord in Svalbard and interpreted as the fluctuations induced by internal waves revealed the existence of short-period internal waves with an amplitude of approximately 1 m and a period of approximately 5–10 min that correlate with the ice cover fluctuations of the same period with an amplitude of a few millimeters.

Highlights

We analyze the measurements of temperature, velocity, and pressure at the bottom to study the influence of internal waves on the ice cover
Inconsistent with the experimental data obtained for relatively deep parts of the Arctic Ocean [3,4,5,6] and contradicts the theoretical results [7, 8], according to which internal waves may be reflected in the fluctuations of the ice cover at frequencies comparable with the BruntVaisalafrequency
Scientists from the Shirshov Institute of Oceanology (Russian Academy of Sciences) and The University Centre in Svalbard (UNIS) carried out marine studies in the shallow Van Mijen Fjord in Svalbard to perform experimental tests of the theoretical conclusion concerning the possible influence of short internal waves on the fluctuations of the compact ice cover

Summary

Introduction

We analyze the measurements of temperature, velocity, and pressure at the bottom to study the influence of internal waves on the ice cover. In the “rigid lid” approximation, the vertical velocity at the surface is assumed to be equal to zero; due to the kinematic condition, the internal waves cannot cause any vertical displacements of the ice cover. Such conclusion is, inconsistent with the experimental data obtained for relatively deep parts of the Arctic Ocean [3,4,5,6] and contradicts the theoretical results [7, 8], according to which internal waves may be reflected in the fluctuations of the ice cover at frequencies comparable with the BruntVaisalafrequency.

Brief Theory of Internal Waves under an Ice Cover

Measurements of Internal Waves in the Van Mijen Fjord under the Ice Cover

Findings

Discussion and Conclusions