Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Ocean model diagnosis of variability in the South Indian Ocean

Includes bibliographical references (leaves 180-195).

Saved in:
Bibliographic Details
Main Author: Hermes, Juliet C
Other Authors: Reason, Chris
Format: Thesis
Language:English
Published: Department of Oceanography 2014
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613286347833344
access_status_str Open Access
author Hermes, Juliet C
author2 Reason, Chris
author_browse Hermes, Juliet C
Reason, Chris
author_facet Reason, Chris
Hermes, Juliet C
author_sort Hermes, Juliet C
collection Thesis
description Includes bibliographical references (leaves 180-195).
format Thesis
id oai:open.uct.ac.za:11427/8649
institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:33:43.673Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Department of Oceanography
publisherStr Department of Oceanography
record_format dspace
source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/8649 Ocean model diagnosis of variability in the South Indian Ocean Hermes, Juliet C Reason, Chris Lutjeharms, Johann R E Oceanography Includes bibliographical references (leaves 180-195). Evidence exists that sea surface temperature (SST) variability in the South Indian Ocean may significantly influence weather and climate patterns in the southern African region. SST, in tum, can be influenced by variability in ocean fluxes, observations of which are limited in the South Indian Ocean and it is necessary to augment them with estimates derived from models. Two sets of variability in this region are examined in this thesis. The first concerns the large-scale interannual variability of the oceans neighbouring South Africa and the second, inter-ocean fluxes south of Africa on meso-through to interannual timescales. In terms of the former, a global ocean model forced with 50 years of NCEP (National Centre for Environmental Prediction) re-analyses winds and heat fluxes, has been used to investigate the evolution and forcing of interannual SST variability in the South Indian Ocean and co-variability patterns in the South Atlantic. Secondly, an eddy- permitting model is used to investigate volume, heat and salt fluxes in the oceanic region south of Africa and the effect of variations in the strength of wind forcing. Interannual dipole-like SST variability in the South Indian and South Atlantic Oceans were realistically simulated using the global ocean model, ORCA2. The model results imply that there are connections between large-scale modulations of the midlatitude atmospheric circulation of the Southern Hemisphere and co-evolving SST variability in the South Atlantic and South Indian Oceans. The atmospheric variability results in an increase (decrease) in strength of the anticyclonic wind fields over each ocean during positive (negative) dipole events. The resulting wind anomalies lead to changes in surface heat fluxes, short wave radiation, meridional Ekman heat transport and upwelling, all of which contribute to the evolution of these SST dipole patterns. Evidence is found of links between these dipole patterns and the Antarctic Oscillation and ENSO (El Niño Southern Oscillation). 2014-10-20T07:45:55Z 2014-10-20T07:45:55Z 2005 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/8649 eng application/pdf Department of Oceanography Faculty of Science University of Cape Town
spellingShingle Oceanography
Hermes, Juliet C
Ocean model diagnosis of variability in the South Indian Ocean
thesis_degree_str Doctoral
title Ocean model diagnosis of variability in the South Indian Ocean
title_full Ocean model diagnosis of variability in the South Indian Ocean
title_fullStr Ocean model diagnosis of variability in the South Indian Ocean
title_full_unstemmed Ocean model diagnosis of variability in the South Indian Ocean
title_short Ocean model diagnosis of variability in the South Indian Ocean
title_sort ocean model diagnosis of variability in the south indian ocean
topic Oceanography
url http://hdl.handle.net/11427/8649
work_keys_str_mv AT hermesjulietc oceanmodeldiagnosisofvariabilityinthesouthindianocean