Ocean 2D eddy energy fluxes from small mesoscale processes with SWOT
-
Published:2023-10-06
Issue:5
Volume:19
Page:1413-1435
-
ISSN:1812-0792
-
Container-title:Ocean Science
-
language:en
-
Short-container-title:Ocean Sci.
Author:
Carli ElisaORCID, Morrow Rosemary, Vergara OscarORCID, Chevrier Robin, Renault LionelORCID
Abstract
Abstract. We investigate ocean dynamics at different scales in the Agulhas Current system, a region of important interocean exchange of heat and energy. While ocean observations and some of the most advanced climate models capture the larger mesoscale dynamics (> 100 km), the smaller-scale fronts and eddies are underrepresented. The recently launched NASA–CNES Surface Water and Ocean Topography (SWOT) wide-swath altimeter mission observes the smaller ocean geostrophic scales down to 15 km in wavelength globally. Here we will analyse different eddy diagnostics in the Agulhas Current region and quantify the contributions from the larger mesoscales observable today and the smaller scales to be observed with SWOT. Surface geostrophic diagnostics of eddy kinetic energy, strain, and energy cascades are estimated from modelled sea surface height (SSH) fields of the Massachusetts Institute of Technology general circulation model (MITgcm) latitude–longitude polar cap (LLC4320) simulation subsampled at 1/10∘. In this region, the smaller scales (<150 km) have a strong signature on the horizontal geostrophic strain rate and for all eddy diagnostics in the Western Boundary Current and along the meandering Agulhas Extension. We investigate the horizontal cascade of energy using a coarse-graining technique, and we observe that the wavelength range where the inverse cascade occurs is biased towards larger mesoscale wavelengths with today’s altimetric sampling. We also calculate the projected sampling of the eddy diagnostics under the SWOT swaths built with the NASA–CNES simulator to include the satellite position and realistic noise. For the swaths, a neural network noise mitigation method is implemented to reduce the residual SWOT random error before calculating eddy diagnostics. In terms of SSH, observable wavelengths of 15 to 20 km are retrieved after neural network noise mitigation, as opposed to wavelengths larger than 40 km before the noise reduction.
Funder
Centre National d’Etudes Spatiales
Publisher
Copernicus GmbH
Subject
Cell Biology,Developmental Biology,Embryology,Anatomy
Reference94 articles.
1. Aluie, H., Hecht, M., and Vallis, G.: Mapping the Energy Cascade in the North
Atlantic Ocean: The Coarse-Graining Approach, J. Phys. Oceanogr., 48, 225–244,
https://doi.org/10.1175/JPO-D-17-0100.1, 2017. a, b 2. Arbic, B. K., Polzin, K. L., Scott, R. B., Richman, J. G., and Shriver, J. F.:
On Eddy Viscosity, Energy Cascades, and the Horizontal Resolution
of Gridded Satellite Altimeter Products, J. Phys. Oceanogr., 43,
283–300, https://doi.org/10.1175/JPO-D-11-0240.1, 2013. a 3. Arbic, B. K., Elipot, S., Brasch, J. M., Menemenlis, D., Ponte, A. L., Shriver,
J. F., Yu, X., Zaron, E. D., Alford, M. H., Buijsman, M. C., Abernathey, R.,
Garcia, D., Guan, L., Martin, P. E., and Nelson, A. D.: Near‐Surface
Oceanic Kinetic Energy Distributions From Drifter Observations
and Numerical Models, J. Geophys. Res., 127, 10, https://doi.org/10.1029/2022JC018551,
2022. a, b, c 4. Ballarotta, M., Ubelmann, C., Pujol, M.-I., Taburet, G., Fournier, F., Legeais, J.-F., Faugère, Y., Delepoulle, A., Chelton, D., Dibarboure, G., and Picot, N.: On the resolutions of ocean altimetry maps, Ocean Sci., 15, 1091–1109, https://doi.org/10.5194/os-15-1091-2019, 2019. a, b, c 5. Beal, L. M., De Ruijter, W. P. M., Biastoch, A., Zahn, R., SCOR/WCRP/IAPSO
Working Group 136, Cronin, M., Hermes, J., Lutjeharms, J., Quartly, G.,
Tozuka, T., Baker-Yeboah, S., Bornman, T., Cipollini, P., Dijkstra, H., Hall,
I., Park, W., Peeters, F., Penven, P., Ridderinkhof, H., and Zinke, J.: On
the role of the Agulhas system in ocean circulation and climate, Nature,
472, 429–436, https://doi.org/10.1038/nature09983, 2011. a
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|