Optimizing velocities and transports for complex coastal regions and archipelagos

We derive and apply a methodology for the initialization of velocity and transport fields in complex multiply-connected regions with multiscale dynamics. The result is initial fields that are consistent with observations, complex geometry and dynamics, and that can simulate the evolution of ocean pr...

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Main Authors: Haley, Patrick, Agarwal, Arpit, Lermusiaux, Pierre
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Language:en_US
Published: Elsevier B.V. 2017
Online Access:http://hdl.handle.net/1721.1/108582
https://orcid.org/0000-0002-1869-3883
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author Haley, Patrick
Agarwal, Arpit
Lermusiaux, Pierre
author2 Massachusetts Institute of Technology. Department of Mechanical Engineering
author_facet Massachusetts Institute of Technology. Department of Mechanical Engineering
Haley, Patrick
Agarwal, Arpit
Lermusiaux, Pierre
author_sort Haley, Patrick
collection MIT
description We derive and apply a methodology for the initialization of velocity and transport fields in complex multiply-connected regions with multiscale dynamics. The result is initial fields that are consistent with observations, complex geometry and dynamics, and that can simulate the evolution of ocean processes without large spurious initial transients. A class of constrained weighted least squares optimizations is defined to best fit first-guess velocities while satisfying the complex bathymetry, coastline and divergence strong constraints. A weak constraint towards the minimum inter-island transports that are in accord with the first-guess velocities provides important velocity corrections in complex archipelagos. In the optimization weights, the minimum distance and vertical area between pairs of coasts are computed using a Fast Marching Method. Additional information on velocity and transports are included as strong or weak constraints. We apply our methodology around the Hawaiian islands of Kauai/Niihau, in the Taiwan/Kuroshio region and in the Philippines Archipelago. Comparisons with other common initialization strategies, among hindcasts from these initial conditions (ICs), and with independent in situ observations show that our optimization corrects transports, satisfies boundary conditions and redirects currents. Differences between the hindcasts from these different ICs are found to grow for at least 2–3 weeks. When compared to independent in situ observations, simulations from our optimized ICs are shown to have the smallest errors.
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spelling mit-1721.1/1085822022-09-29T09:49:28Z Optimizing velocities and transports for complex coastal regions and archipelagos Haley, Patrick Agarwal, Arpit Lermusiaux, Pierre Massachusetts Institute of Technology. Department of Mechanical Engineering Haley, Patrick Agarwal, Arpit Lermusiaux, Pierre We derive and apply a methodology for the initialization of velocity and transport fields in complex multiply-connected regions with multiscale dynamics. The result is initial fields that are consistent with observations, complex geometry and dynamics, and that can simulate the evolution of ocean processes without large spurious initial transients. A class of constrained weighted least squares optimizations is defined to best fit first-guess velocities while satisfying the complex bathymetry, coastline and divergence strong constraints. A weak constraint towards the minimum inter-island transports that are in accord with the first-guess velocities provides important velocity corrections in complex archipelagos. In the optimization weights, the minimum distance and vertical area between pairs of coasts are computed using a Fast Marching Method. Additional information on velocity and transports are included as strong or weak constraints. We apply our methodology around the Hawaiian islands of Kauai/Niihau, in the Taiwan/Kuroshio region and in the Philippines Archipelago. Comparisons with other common initialization strategies, among hindcasts from these initial conditions (ICs), and with independent in situ observations show that our optimization corrects transports, satisfies boundary conditions and redirects currents. Differences between the hindcasts from these different ICs are found to grow for at least 2–3 weeks. When compared to independent in situ observations, simulations from our optimized ICs are shown to have the smallest errors. 2017-05-02T15:45:48Z 2017-05-02T15:45:48Z 2015-03 2015-02 Article http://purl.org/eprint/type/JournalArticle 14635003 http://hdl.handle.net/1721.1/108582 Haley, Patrick J., Arpit Agarwal, and Pierre F.J. Lermusiaux. “Optimizing Velocities and Transports for Complex Coastal Regions and Archipelagos.” Ocean Modelling 89 (May 2015): 1–28. https://orcid.org/0000-0002-1869-3883 en_US http://dx.doi.org/10.1016/j.ocemod.2015.02.005 Ocean Modelling Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier B.V. Prof. Lermusiaux via Angie Locknar
spellingShingle Haley, Patrick
Agarwal, Arpit
Lermusiaux, Pierre
Optimizing velocities and transports for complex coastal regions and archipelagos
title Optimizing velocities and transports for complex coastal regions and archipelagos
title_full Optimizing velocities and transports for complex coastal regions and archipelagos
title_fullStr Optimizing velocities and transports for complex coastal regions and archipelagos
title_full_unstemmed Optimizing velocities and transports for complex coastal regions and archipelagos
title_short Optimizing velocities and transports for complex coastal regions and archipelagos
title_sort optimizing velocities and transports for complex coastal regions and archipelagos
url http://hdl.handle.net/1721.1/108582
https://orcid.org/0000-0002-1869-3883
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