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Kelvin waves around Antarctica

Citation

Kusahara, K and Ohshima, KI, Kelvin waves around Antarctica, Journal of Physical Oceanography, 44 pp. 2909-2920. ISSN 0022-3670 (2014) [Refereed Article]


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Copyright Statement

Copyright 2014 American Meteorological Society

DOI: doi:10.1175/JPO-D-14-0051.1

Abstract

The Southern Ocean allows circumpolar structure and the Antarctic coastline plays a role as a waveguide for oceanic Kelvin waves. Under the cyclic conditions, the horizontal wavenumbers and frequencies for circumpolarly propagating waves are quantized, with horizontal wavenumbers 1, 2, and 3, corresponding to periods of about 32, 16, and 11 h, respectively. At these frequencies, westward-propagating signals are detected in sea level variation observed at Antarctic coastal stations. The occurrence frequency of westward-propagating signals far exceeds the statistical significance, and the phase speed of the observed signal agrees well with the theoretical phase speed of external Kelvin waves. Therefore, this study concludes that the observed, westward-propagating sea level variability is a signal of the external Kelvin waves of wavenumbers 1, 2, and 3 around Antarctica. A series of numerical model experiments confirms that Kelvin waves around Antarctica are driven by surface air pressure and that these waves are excited not only by local forcing over the Southern Ocean, but also by remote forcing over the Pacific Ocean. Sea level variations generated over the Pacific Ocean can travel to the western side of the South American coast and cross over Drake Passage to the Antarctic continent, constituting a part of the Kelvin waves around Antarctica.

Item Details

Item Type:Refereed Article
Keywords:external Kelvin waves
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical Oceanography
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Antarctic and Sub-Antarctic Oceanography
Author:Kusahara, K (Dr Kazuya Kusahara)
ID Code:109883
Year Published:2014
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2016-07-06
Last Modified:2016-10-06
Downloads:38 View Download Statistics

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