Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage
This study discusses the upper-ocean (0-200 m) horizontal wavenumber spectra in the Drake Passage from 13 yr of shipboard ADCP measurements, altimeter data, and a high-resolution numerical simulation. At scales between 10 and 200 km, the ADCP kinetic energy spectra approximately follow a k-3 power l...
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ftcdlib:oai:escholarship.org:ark:/13030/qt6zd163zg 2023-06-18T03:40:24+02:00 Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage Rocha, Cesar B Chereskin, Teresa K Gille, Sarah T Menemenlis, Dimitris 601 - 620 2016-02-01 application/pdf https://escholarship.org/uc/item/6zd163zg unknown eScholarship, University of California qt6zd163zg https://escholarship.org/uc/item/6zd163zg public Journal of Physical Oceanography, vol 46, iss 2 Ship observations Atm/Ocean Structure/ Phenomena Eddies Satellite observations Observational techniques and algorithms Oceanic mixed layer Tides Oceanography Maritime Engineering article 2016 ftcdlib 2023-06-05T18:01:14Z This study discusses the upper-ocean (0-200 m) horizontal wavenumber spectra in the Drake Passage from 13 yr of shipboard ADCP measurements, altimeter data, and a high-resolution numerical simulation. At scales between 10 and 200 km, the ADCP kinetic energy spectra approximately follow a k-3 power law. The observed flows are more energetic at the surface, but the shape of the kinetic energy spectra is independent of depth. These characteristics resemble predictions of isotropic interior quasigeostrophic turbulence. The ratio of across-track to along-track kinetic energy spectra, however, significantly departs from the expectation of isotropic interior quasigeostrophic turbulence. The inconsistency is dramatic at scales smaller than 40 km. A Helmholtz decomposition of the ADCP spectra and analyses of synthetic and numerical model data show that horizontally divergent, ageostrophic flows account for the discrepancy between the observed spectra and predictions of isotropic interior quasigeostrophic turbulence. In Drake Passage, ageostrophic motions appear to be dominated by inertia-gravity waves and account for about half of the near-surface kinetic energy at scales between 10 and 40 km. Model results indicate that ageostrophic flows imprint on the sea surface, accounting for about half of the sea surface height variance between 10 and 40 km. Article in Journal/Newspaper Drake Passage University of California: eScholarship Drake Passage |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Ship observations Atm/Ocean Structure/ Phenomena Eddies Satellite observations Observational techniques and algorithms Oceanic mixed layer Tides Oceanography Maritime Engineering |
spellingShingle |
Ship observations Atm/Ocean Structure/ Phenomena Eddies Satellite observations Observational techniques and algorithms Oceanic mixed layer Tides Oceanography Maritime Engineering Rocha, Cesar B Chereskin, Teresa K Gille, Sarah T Menemenlis, Dimitris Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
topic_facet |
Ship observations Atm/Ocean Structure/ Phenomena Eddies Satellite observations Observational techniques and algorithms Oceanic mixed layer Tides Oceanography Maritime Engineering |
description |
This study discusses the upper-ocean (0-200 m) horizontal wavenumber spectra in the Drake Passage from 13 yr of shipboard ADCP measurements, altimeter data, and a high-resolution numerical simulation. At scales between 10 and 200 km, the ADCP kinetic energy spectra approximately follow a k-3 power law. The observed flows are more energetic at the surface, but the shape of the kinetic energy spectra is independent of depth. These characteristics resemble predictions of isotropic interior quasigeostrophic turbulence. The ratio of across-track to along-track kinetic energy spectra, however, significantly departs from the expectation of isotropic interior quasigeostrophic turbulence. The inconsistency is dramatic at scales smaller than 40 km. A Helmholtz decomposition of the ADCP spectra and analyses of synthetic and numerical model data show that horizontally divergent, ageostrophic flows account for the discrepancy between the observed spectra and predictions of isotropic interior quasigeostrophic turbulence. In Drake Passage, ageostrophic motions appear to be dominated by inertia-gravity waves and account for about half of the near-surface kinetic energy at scales between 10 and 40 km. Model results indicate that ageostrophic flows imprint on the sea surface, accounting for about half of the sea surface height variance between 10 and 40 km. |
format |
Article in Journal/Newspaper |
author |
Rocha, Cesar B Chereskin, Teresa K Gille, Sarah T Menemenlis, Dimitris |
author_facet |
Rocha, Cesar B Chereskin, Teresa K Gille, Sarah T Menemenlis, Dimitris |
author_sort |
Rocha, Cesar B |
title |
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
title_short |
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
title_full |
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
title_fullStr |
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
title_full_unstemmed |
Mesoscale to Submesoscale Wavenumber Spectra in Drake Passage |
title_sort |
mesoscale to submesoscale wavenumber spectra in drake passage |
publisher |
eScholarship, University of California |
publishDate |
2016 |
url |
https://escholarship.org/uc/item/6zd163zg |
op_coverage |
601 - 620 |
geographic |
Drake Passage |
geographic_facet |
Drake Passage |
genre |
Drake Passage |
genre_facet |
Drake Passage |
op_source |
Journal of Physical Oceanography, vol 46, iss 2 |
op_relation |
qt6zd163zg https://escholarship.org/uc/item/6zd163zg |
op_rights |
public |
_version_ |
1769005410985967616 |