University of Tasmania
Browse
Heil_Massom_Allison_Worby_Lytle_JGR_2009.pdf (1.26 MB)

Role of off-shelf to on-shelf transitions for East Antarctic sea ice dynamics during spring 2003

Download (1.26 MB)
journal contribution
posted on 2023-05-18, 10:17 authored by Petra HeilPetra Heil, Robert MassomRobert Massom, Ian AllisonIan Allison, Worby, AP, Lytle, VI
[1] During austral spring 2003, mesoscale sea ice drift and deformation off East Antarctica were investigated using in situ data from a nine-buoy array. Upon deployment, the array comprised an area of about 4000 km2 with a mean ice concentration of 96%. Half-hourly sea ice velocities were coherent across all buoys at zonal (meridional) separations of less than 160 km (70 km). Regional cross-spectral correlation was high at synoptic scales and also at semidiurnal periods off the continental shelf. Atmospheric synoptic-scale forcing explained in excess of 85% of the ice drift variability. This is significantly more than found in the Weddell Sea, where significant ice drift variability is derived from oceanic forcing. Peak frequencies of semidiurnal contributions covaried with latitude and are largely associated with the inertial response. Over the continental shelf, coincident diurnal and semidiurnal variances in ice motion arose from tidal forcing. Net divergence over 37 days resulted in an expansion to 270% of the initial area, although regional ice concentration reduced only slightly. High-frequency processes, namely inertial response and to a lesser degree tidal forcing, dominated the variability of all deformation parameters. In contrast to ice motion, low-frequency processes played a secondary role in sea ice deformation. This high-frequency dominance is similar to what has been found in the Weddell Sea, although many observations there were limited to the continental shelf, where tidal processes dominate. Sea ice motion and deformation were not affected by a seasonal transition, nor did the regional ice characteristics show any signal of seasonal change. Instead, local ice dynamics were strongly influenced by bathymetrically dependent processes.

History

Publication title

Journal of Geophysical Research

Volume

114

Issue

C9

Pagination

1-20

ISSN

0148-0227

Department/School

Institute for Marine and Antarctic Studies

Publisher

Amer Geophysical Union

Place of publication

2000 Florida Ave Nw, Washington, USA, Dc, 20009

Rights statement

Copyright 2009 American Geophysical Union

Repository Status

  • Open

Socio-economic Objectives

Antarctic and Southern Ocean oceanic processes

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC