Properties of the lateral mesoscale eddy-induced transport in a high-resolution ocean model: beyond the flux-gradient relation
File(s)JPO-D-22-0108_R1.pdf (4.52 MB)
Accepted version
Author(s)
Lu, Yueyang
Kamenkovich, Igor
Berloff, Pavel
Type
Journal Article
Abstract
Lateral mesoscale eddy-induced tracer transport is traditionally represented in coarse-resolution models by the flux–gradient relation. In its most complete form, the relation assumes the eddy tracer flux as a product of the large-scale tracer concentration gradient and an eddy transport coefficient tensor. However, several recent studies reported that the tensor has significant spatiotemporal complexity and is not uniquely defined, that is, it is sensitive to the tracer distributions and to the presence of nondivergent (“rotational”) components of the eddy flux. These issues could lead to significant biases in the representation of the eddy-induced transport. Using a high-resolution tracer model of the Gulf Stream region, we examine the diffusive and advective properties of lateral eddy-induced transport of dynamically passive tracers, reevaluate the utility of the flux–gradient relation, and propose an alternative approach based on modeling the local eddy forcing by a combination of diffusion and generalized eddy-induced advection. Mesoscale eddies are defined by a scale-based spatial filtering, which leads to the importance of new eddy-induced terms, including eddy-mean covariances in the eddy fluxes. The results show that the biases in representing these terms are noticeably reduced by the new approach. A series of targeted simulations in the high-resolution model further demonstrates that the approach outperforms the flux–gradient model in reproducing the stirring and dispersing effect of eddies. Our study indicates potential to upgrade the traditional flux–gradient relation for representing the eddy-induced tracer transport.
Date Issued
2022-12
Date Acceptance
2022-08-03
Citation
Journal of Physical Oceanography, 2022, 52 (12), pp.3273-3295
ISSN
0022-3670
Publisher
American Meteorological Society
Start Page
3273
End Page
3295
Journal / Book Title
Journal of Physical Oceanography
Volume
52
Issue
12
Copyright Statement
This is the accepted version of the following article: Lu, Y., I. Kamenkovich, and P. Berloff, 2022: Properties of the Lateral Mesoscale Eddy-Induced Transport in a High-Resolution Ocean Model: Beyond the Flux–Gradient Relation. J. Phys. Oceanogr., 52, 3273–3295, which has been published in final form at https://doi.org/10.1175/JPO-D-22-0108.1. Copyright © 2023 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000913390900021&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=a2bf6146997ec60c407a63945d4e92bb
Subjects
CIRCULATION
DIFFUSIVITY
Eddies
EDDIES
General circulation models
Mesoscale processes
Mixing
NORTH-ATLANTIC OCEAN
Oceanography
PARAMETERIZATION
PATHWAYS
Physical Sciences
Science & Technology
STATISTICS
Subgrid-scale processes
SUPPRESSION
TRACER
Tracers
Publication Status
Published
Date Publish Online
2022-11-22