The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures
Tests of the new Rossby wave theories that have been developed over the past decade to account for discrepancies between theoretical wave speeds and those observed by satellite altimeters have focused primarily on the surface signature of such waves. It appears, however, that the surface signature o...
Published in: | Ocean Science |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
European Geosciences Union
2012
|
Subjects: | |
Online Access: | https://centaur.reading.ac.uk/34403/ https://centaur.reading.ac.uk/34403/1/os-8-19-2012-1.pdf http://www.ocean-sci.net/8/19/2012/os-8-19-2012.html |
id |
ftunivreading:oai:centaur.reading.ac.uk:34403 |
---|---|
record_format |
openpolar |
spelling |
ftunivreading:oai:centaur.reading.ac.uk:34403 2024-06-23T07:55:19+00:00 The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures Hunt, F. K. Tailleux, Remi Hirschi, J. J.-M. 2012 text https://centaur.reading.ac.uk/34403/ https://centaur.reading.ac.uk/34403/1/os-8-19-2012-1.pdf http://www.ocean-sci.net/8/19/2012/os-8-19-2012.html en eng European Geosciences Union https://centaur.reading.ac.uk/34403/1/os-8-19-2012-1.pdf Hunt, F. K., Tailleux, R. <https://centaur.reading.ac.uk/view/creators/90000948.html> orcid:0000-0001-8998-9107 and Hirschi, J. J.-M. (2012) The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures. Ocean Science, 8 (1). pp. 19-35. ISSN 1812-0784 doi: https://doi.org/10.5194/os-8-19-2012 <https://doi.org/10.5194/os-8-19-2012> cc_by Article PeerReviewed 2012 ftunivreading https://doi.org/10.5194/os-8-19-2012 2024-06-11T15:01:09Z Tests of the new Rossby wave theories that have been developed over the past decade to account for discrepancies between theoretical wave speeds and those observed by satellite altimeters have focused primarily on the surface signature of such waves. It appears, however, that the surface signature of the waves acts only as a rather weak constraint, and that information on the vertical structure of the waves is required to better discriminate between competing theories. Due to the lack of 3-D observations, this paper uses high-resolution model data to construct realistic vertical structures of Rossby waves and compares these to structures predicted by theory. The meridional velocity of a section at 24° S in the Atlantic Ocean is pre-processed using the Radon transform to select the dominant westward signal. Normalized profiles are then constructed using three complementary methods based respectively on: (1) averaging vertical profiles of velocity, (2) diagnosing the amplitude of the Radon transform of the westward propagating signal at different depths, and (3) EOF analysis. These profiles are compared to profiles calculated using four different Rossby wave theories: standard linear theory (SLT), SLT plus mean flow, SLT plus topographic effects, and theory including mean flow and topographic effects. Our results support the classical theoretical assumption that westward propagating signals have a well-defined vertical modal structure associated with a phase speed independent of depth, in contrast with the conclusions of a recent study using the same model but for different locations in the North Atlantic. The model structures are in general surface intensified, with a sign reversal at depth in some regions, notably occurring at shallower depths in the East Atlantic. SLT provides a good fit to the model structures in the top 300 m, but grossly overestimates the sign reversal at depth. The addition of mean flow slightly improves the latter issue, but is too surface intensified. SLT plus topography rectifies the ... Article in Journal/Newspaper North Atlantic CentAUR: Central Archive at the University of Reading Ocean Science 8 1 19 35 |
institution |
Open Polar |
collection |
CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
Tests of the new Rossby wave theories that have been developed over the past decade to account for discrepancies between theoretical wave speeds and those observed by satellite altimeters have focused primarily on the surface signature of such waves. It appears, however, that the surface signature of the waves acts only as a rather weak constraint, and that information on the vertical structure of the waves is required to better discriminate between competing theories. Due to the lack of 3-D observations, this paper uses high-resolution model data to construct realistic vertical structures of Rossby waves and compares these to structures predicted by theory. The meridional velocity of a section at 24° S in the Atlantic Ocean is pre-processed using the Radon transform to select the dominant westward signal. Normalized profiles are then constructed using three complementary methods based respectively on: (1) averaging vertical profiles of velocity, (2) diagnosing the amplitude of the Radon transform of the westward propagating signal at different depths, and (3) EOF analysis. These profiles are compared to profiles calculated using four different Rossby wave theories: standard linear theory (SLT), SLT plus mean flow, SLT plus topographic effects, and theory including mean flow and topographic effects. Our results support the classical theoretical assumption that westward propagating signals have a well-defined vertical modal structure associated with a phase speed independent of depth, in contrast with the conclusions of a recent study using the same model but for different locations in the North Atlantic. The model structures are in general surface intensified, with a sign reversal at depth in some regions, notably occurring at shallower depths in the East Atlantic. SLT provides a good fit to the model structures in the top 300 m, but grossly overestimates the sign reversal at depth. The addition of mean flow slightly improves the latter issue, but is too surface intensified. SLT plus topography rectifies the ... |
format |
Article in Journal/Newspaper |
author |
Hunt, F. K. Tailleux, Remi Hirschi, J. J.-M. |
spellingShingle |
Hunt, F. K. Tailleux, Remi Hirschi, J. J.-M. The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
author_facet |
Hunt, F. K. Tailleux, Remi Hirschi, J. J.-M. |
author_sort |
Hunt, F. K. |
title |
The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
title_short |
The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
title_full |
The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
title_fullStr |
The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
title_full_unstemmed |
The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
title_sort |
vertical structure of oceanic rossby waves: a comparison of high-resolution model data to theoretical vertical structures |
publisher |
European Geosciences Union |
publishDate |
2012 |
url |
https://centaur.reading.ac.uk/34403/ https://centaur.reading.ac.uk/34403/1/os-8-19-2012-1.pdf http://www.ocean-sci.net/8/19/2012/os-8-19-2012.html |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://centaur.reading.ac.uk/34403/1/os-8-19-2012-1.pdf Hunt, F. K., Tailleux, R. <https://centaur.reading.ac.uk/view/creators/90000948.html> orcid:0000-0001-8998-9107 and Hirschi, J. J.-M. (2012) The vertical structure of oceanic Rossby waves: a comparison of high-resolution model data to theoretical vertical structures. Ocean Science, 8 (1). pp. 19-35. ISSN 1812-0784 doi: https://doi.org/10.5194/os-8-19-2012 <https://doi.org/10.5194/os-8-19-2012> |
op_rights |
cc_by |
op_doi |
https://doi.org/10.5194/os-8-19-2012 |
container_title |
Ocean Science |
container_volume |
8 |
container_issue |
1 |
container_start_page |
19 |
op_container_end_page |
35 |
_version_ |
1802647865611255808 |