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Open Access. Powered by Scholars. Published by Universities.®

2019

Portland State University

Series

Submarine topography

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Toward Realistic Nonstationarity Of Semidiurnal Baroclinic Tides In A Hydrodynamicmodel, Arin D. Nelson, Brian K. Arbic, Edward Zaron, Anna Savage, James G. Richman, Maarten C. Buijsman, Jay F. Shriver Aug 2019

Toward Realistic Nonstationarity Of Semidiurnal Baroclinic Tides In A Hydrodynamicmodel, Arin D. Nelson, Brian K. Arbic, Edward Zaron, Anna Savage, James G. Richman, Maarten C. Buijsman, Jay F. Shriver

Civil and Environmental Engineering Faculty Publications and Presentations

Semidiurnal baroclinic tide sea surface height (SSH) variance and semidiurnal nonstationary variance fraction (SNVF) are compared between a hydrodynamic model and altimetry for the low- to middle-latitude global ocean. Tidal frequencies are aliased by ∼10-day altimeter sampling, which makes it impossible to unambiguously identify nonstationary tidal signals from the observations. In order to better understand altimeter sampling artifacts, the model was analyzed using its native hourly outputs and by subsampling it in the same manner as altimeters. Different estimates of the semidiurnal nonstationary and total SSH variance are obtained with the model depending on whether they are identified in the ...


Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey Aug 2019

Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey

Civil and Environmental Engineering Faculty Publications and Presentations

The surface kinetic energy of a 1/48◦ global ocean simulation and its distribution as a function of frequency and location are compared with the one estimated from 15,329 globally distributed surface drifter observations at hourly resolution. These distributions follow similar patterns with a dominant low-frequency component and well-defined tidal and near-inertial peaks globally. Quantitative differences are identified with deficits of low-frequency energy near the equator (factor 2) and at near-inertial frequencies (factor 3) and an excess of energy at semidiurnal frequencies (factor 4) for the model. Owing to its hourly resolution and its near-global spatial coverage, the array ...


Simultaneous Estimation Of Ocean Tides And Underwater Topography In The Weddell Sea, Edward D. Zaron May 2019

Simultaneous Estimation Of Ocean Tides And Underwater Topography In The Weddell Sea, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

A new model for theM2, S2, K1, and O1 tides in the Weddell Sea is developed by assimilating CryoSat-2 data into a barotropic tide model. A variational approach is used, which explicitly allows for errors in the water depth, that is, the bottom topography in open water and the water column thickness under floating ice shelves, so that an optimized estimate of the topography is obtained together with the tidal fields. In preparation for assimilation, the sensitivity of the tidal elevation to the interfacial drag at the sea floor and the ice-water interface (under the floating ice shelves) is investigated ...