Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field
Clustering of tracers floating on the ocean surface and evolving due to combined velocity fields consisting of a deterministic mesoscale component and a kinematic random component is analysed. The random component represents the influence of submesoscale motions. A theory of exponential clustering i...
Published in: | Geophysical & Astrophysical Fluid Dynamics |
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Language: | English |
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Taylor and Francis
2020
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Online Access: | http://hdl.handle.net/10044/1/81454 https://doi.org/10.1080/03091929.2020.1786551 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/81454 2023-05-15T18:18:44+02:00 Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field Stepanov, D Ryzhov, EA Berloff, P Koshel, K Natural Environment Research Council (NERC) The Leverhulme Trust 2020-06-19 http://hdl.handle.net/10044/1/81454 https://doi.org/10.1080/03091929.2020.1786551 English eng Taylor and Francis Geophysical and Astrophysical Fluid Dynamics 0309-1929 http://hdl.handle.net/10044/1/81454 doi:10.1080/03091929.2020.1786551 NE/R011567/1 RPG-2019-024 NE/T002220/1 © 2020 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis in Geophysical & Astrophysical Fluid Dynamics on 09 July 2020, available online: https://doi.org/10.1080/03091929.2020.1786551 714 690 Science & Technology Physical Sciences Technology Astronomy & Astrophysics Geochemistry & Geophysics Mechanics Mesoscale submesoscale steady and unsteady flows tracer clustering tracer mixing STATISTICAL TOPOGRAPHY ELLIPSOIDAL VORTEX PASSIVE TRACERS SEA-ICE TRANSPORT DEFORMATION DIFFUSION VORTICES DYNAMICS ACCUMULATION CIRCULATION DISPERSION Fluids & Plasmas Journal Article 2020 ftimperialcol https://doi.org/10.1080/03091929.2020.1786551 2021-07-15T22:39:24Z Clustering of tracers floating on the ocean surface and evolving due to combined velocity fields consisting of a deterministic mesoscale component and a kinematic random component is analysed. The random component represents the influence of submesoscale motions. A theory of exponential clustering in random velocity fields is applied to characterise the obtained clustering scenarios in both steady and unsteady time-dependent mesoscale flows, as simulated by a comprehensive realistic, eddy-resolving, general circulation model for the Japan/East Sea. The mesoscale flow field abounds in transient eddy-like patterns modulating and branching the main currents, and the underlying time-mean flow component features closed recirculation zones that can entrap the tracer. The submesoscale flow component is modelled kinematically, as a divergent random velocity field with a prescribed correlation radius and variance. The combined flow induces tracer clustering, that is, the exponential growth of tracer density in patches with vanishing areas. The statistical topography methodology, which provides integral characteristics to quantify the emerging clusters, uncovers drastic dependence of the clustering rates on whether the mesoscale flow component is taken to be steady or time-dependent. The former situation favours robust exponential clustering, similar to the theoretically understood case of purely divergent and zero-mean random velocity. The latter situation, on the contrary, hinders exponential clustering due to significant advection of the tracer out of the nearly enclosed eddies, at the rate faster than the clustering rate. Article in Journal/Newspaper Sea ice Imperial College London: Spiral Geophysical & Astrophysical Fluid Dynamics 114 4-5 690 714 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
English |
topic |
Science & Technology Physical Sciences Technology Astronomy & Astrophysics Geochemistry & Geophysics Mechanics Mesoscale submesoscale steady and unsteady flows tracer clustering tracer mixing STATISTICAL TOPOGRAPHY ELLIPSOIDAL VORTEX PASSIVE TRACERS SEA-ICE TRANSPORT DEFORMATION DIFFUSION VORTICES DYNAMICS ACCUMULATION CIRCULATION DISPERSION Fluids & Plasmas |
spellingShingle |
Science & Technology Physical Sciences Technology Astronomy & Astrophysics Geochemistry & Geophysics Mechanics Mesoscale submesoscale steady and unsteady flows tracer clustering tracer mixing STATISTICAL TOPOGRAPHY ELLIPSOIDAL VORTEX PASSIVE TRACERS SEA-ICE TRANSPORT DEFORMATION DIFFUSION VORTICES DYNAMICS ACCUMULATION CIRCULATION DISPERSION Fluids & Plasmas Stepanov, D Ryzhov, EA Berloff, P Koshel, K Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
topic_facet |
Science & Technology Physical Sciences Technology Astronomy & Astrophysics Geochemistry & Geophysics Mechanics Mesoscale submesoscale steady and unsteady flows tracer clustering tracer mixing STATISTICAL TOPOGRAPHY ELLIPSOIDAL VORTEX PASSIVE TRACERS SEA-ICE TRANSPORT DEFORMATION DIFFUSION VORTICES DYNAMICS ACCUMULATION CIRCULATION DISPERSION Fluids & Plasmas |
description |
Clustering of tracers floating on the ocean surface and evolving due to combined velocity fields consisting of a deterministic mesoscale component and a kinematic random component is analysed. The random component represents the influence of submesoscale motions. A theory of exponential clustering in random velocity fields is applied to characterise the obtained clustering scenarios in both steady and unsteady time-dependent mesoscale flows, as simulated by a comprehensive realistic, eddy-resolving, general circulation model for the Japan/East Sea. The mesoscale flow field abounds in transient eddy-like patterns modulating and branching the main currents, and the underlying time-mean flow component features closed recirculation zones that can entrap the tracer. The submesoscale flow component is modelled kinematically, as a divergent random velocity field with a prescribed correlation radius and variance. The combined flow induces tracer clustering, that is, the exponential growth of tracer density in patches with vanishing areas. The statistical topography methodology, which provides integral characteristics to quantify the emerging clusters, uncovers drastic dependence of the clustering rates on whether the mesoscale flow component is taken to be steady or time-dependent. The former situation favours robust exponential clustering, similar to the theoretically understood case of purely divergent and zero-mean random velocity. The latter situation, on the contrary, hinders exponential clustering due to significant advection of the tracer out of the nearly enclosed eddies, at the rate faster than the clustering rate. |
author2 |
Natural Environment Research Council (NERC) The Leverhulme Trust |
format |
Article in Journal/Newspaper |
author |
Stepanov, D Ryzhov, EA Berloff, P Koshel, K |
author_facet |
Stepanov, D Ryzhov, EA Berloff, P Koshel, K |
author_sort |
Stepanov, D |
title |
Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
title_short |
Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
title_full |
Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
title_fullStr |
Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
title_full_unstemmed |
Floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
title_sort |
floating tracer clustering in divergent random flows modulated by an unsteady mesoscale ocean field |
publisher |
Taylor and Francis |
publishDate |
2020 |
url |
http://hdl.handle.net/10044/1/81454 https://doi.org/10.1080/03091929.2020.1786551 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
714 690 |
op_relation |
Geophysical and Astrophysical Fluid Dynamics 0309-1929 http://hdl.handle.net/10044/1/81454 doi:10.1080/03091929.2020.1786551 NE/R011567/1 RPG-2019-024 NE/T002220/1 |
op_rights |
© 2020 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis in Geophysical & Astrophysical Fluid Dynamics on 09 July 2020, available online: https://doi.org/10.1080/03091929.2020.1786551 |
op_doi |
https://doi.org/10.1080/03091929.2020.1786551 |
container_title |
Geophysical & Astrophysical Fluid Dynamics |
container_volume |
114 |
container_issue |
4-5 |
container_start_page |
690 |
op_container_end_page |
714 |
_version_ |
1766195401762799616 |