Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain
Motivated by the ubiquity of time series in oceanic data, the relative lack of studies of geostrophic turbulence in the frequency domain, and the interest in quantifying the contributions of intrinsic nonlinearities to oceanic frequency spectra, this paper examines the spectra and spectral fluxes of...
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American Meteorological Society
2013
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| Online Access: | http://hdl.handle.net/1721.1/78649 https://orcid.org/0000-0003-3589-5249 |
| _version_ | 1811095309784186880 |
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| author | Arbic, Brian K. Scott, Robert B. Flierl, Glenn Richard Morten, Andrew J. Richman, James G. Shriver, Jay F. |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Arbic, Brian K. Scott, Robert B. Flierl, Glenn Richard Morten, Andrew J. Richman, James G. Shriver, Jay F. |
| author_sort | Arbic, Brian K. |
| collection | MIT |
| description | Motivated by the ubiquity of time series in oceanic data, the relative lack of studies of geostrophic turbulence in the frequency domain, and the interest in quantifying the contributions of intrinsic nonlinearities to oceanic frequency spectra, this paper examines the spectra and spectral fluxes of surface oceanic geostrophic flows in the frequency domain. Spectra and spectral fluxes are computed from idealized two-layer quasigeostrophic (QG) turbulence models and realistic ocean general circulation models, as well as from gridded satellite altimeter data. The frequency spectra of the variance of streamfunction (akin to sea surface height) and of geostrophic velocity are qualitatively similar in all of these, with substantial variance extending out to low frequencies. The spectral flux Π(ω) of kinetic energy in the frequency ω domain for the QG model documents a tendency for nonlinearity to drive energy toward longer periods, in like manner to the inverse cascade toward larger length scales documented in calculations of the spectral flux Π(k) in the wavenumber k domain. Computations of Π(ω) in the realistic model also display an “inverse temporal cascade.” In satellite altimeter data, some regions are dominated by an inverse temporal cascade, whereas others exhibit a forward temporal cascade. However, calculations performed with temporally and/or spatially filtered output from the models demonstrate that Π(ω) values are highly susceptible to the smoothing inherent in the construction of gridded altimeter products. Therefore, at present it is difficult to say whether the forward temporal cascades seen in some regions in altimeter data represent physics that is missing in the models studied here or merely sampling artifacts. |
| first_indexed | 2024-09-23T16:15:12Z |
| format | Article |
| id | mit-1721.1/78649 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T16:15:12Z |
| publishDate | 2013 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/786492022-09-29T19:08:30Z Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain Arbic, Brian K. Scott, Robert B. Flierl, Glenn Richard Morten, Andrew J. Richman, James G. Shriver, Jay F. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Flierl, Glenn Richard Motivated by the ubiquity of time series in oceanic data, the relative lack of studies of geostrophic turbulence in the frequency domain, and the interest in quantifying the contributions of intrinsic nonlinearities to oceanic frequency spectra, this paper examines the spectra and spectral fluxes of surface oceanic geostrophic flows in the frequency domain. Spectra and spectral fluxes are computed from idealized two-layer quasigeostrophic (QG) turbulence models and realistic ocean general circulation models, as well as from gridded satellite altimeter data. The frequency spectra of the variance of streamfunction (akin to sea surface height) and of geostrophic velocity are qualitatively similar in all of these, with substantial variance extending out to low frequencies. The spectral flux Π(ω) of kinetic energy in the frequency ω domain for the QG model documents a tendency for nonlinearity to drive energy toward longer periods, in like manner to the inverse cascade toward larger length scales documented in calculations of the spectral flux Π(k) in the wavenumber k domain. Computations of Π(ω) in the realistic model also display an “inverse temporal cascade.” In satellite altimeter data, some regions are dominated by an inverse temporal cascade, whereas others exhibit a forward temporal cascade. However, calculations performed with temporally and/or spatially filtered output from the models demonstrate that Π(ω) values are highly susceptible to the smoothing inherent in the construction of gridded altimeter products. Therefore, at present it is difficult to say whether the forward temporal cascades seen in some regions in altimeter data represent physics that is missing in the models studied here or merely sampling artifacts. National Science Foundation (U.S.) (Grant OCE-0960826) 2013-05-01T15:56:30Z 2013-05-01T15:56:30Z 2012-09 2011-08 Article http://purl.org/eprint/type/JournalArticle 0022-3670 1520-0485 http://hdl.handle.net/1721.1/78649 Arbic, Brian K. et al. “Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain*.” Journal of Physical Oceanography 42.9 (2012): 1577–1600. ©2012 American Meteorological Society https://orcid.org/0000-0003-3589-5249 en_US http://dx.doi.org/10.1175/jpo-d-11-0151.1 Journal of Physical Oceanography Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Arbic, Brian K. Scott, Robert B. Flierl, Glenn Richard Morten, Andrew J. Richman, James G. Shriver, Jay F. Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title | Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title_full | Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title_fullStr | Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title_full_unstemmed | Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title_short | Nonlinear Cascades of Surface Oceanic Geostrophic Kinetic Energy in the Frequency Domain |
| title_sort | nonlinear cascades of surface oceanic geostrophic kinetic energy in the frequency domain |
| url | http://hdl.handle.net/1721.1/78649 https://orcid.org/0000-0003-3589-5249 |
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