|   | 
Details
   web
Records
Author (up) Buijsman, M. C.; Arbic, B. K.; Richman, J. G.; Shriver, J. F.; Wallcraft, A. J.; Zamudio, L.
Title Semidiurnal internal tide incoherence in the equatorial Pacific Type $loc['typeJournal Article']
Year 2017 Publication Journal of Geophysical Research – Oceans Abbreviated Journal J. Geophys. Res. Oceans
Volume 12 Issue 7 Pages 5286-5305
Keywords internal tide; nonstationarity; equatorial jets; numerical modeling; tides
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 16
Permanent link to this record
 

 
Author (up) Dukhovskoy, D.S.; Morey, S.L.; Martin, P.J.; O'Brien, J.J.; Cooper, C.
Title Application of a vanishing, quasi-sigma, vertical coordinate for simulation of high-speed, deep currents over the Sigsbee Escarpment in the Gulf of Mexico Type $loc['typeJournal Article']
Year 2009 Publication Ocean Modelling Abbreviated Journal Ocean Modelling
Volume 28 Issue 4 Pages 250-265
Keywords Numerical models; Deep currents; Topographic waves; Numerical truncation error; Vertical discretization; Sigsbee Escarpment; Gulf of Mexico
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-5003 ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 399
Permanent link to this record
 

 
Author (up) Dukhovskoy, D.S.; Morey, S.L.; O'Brien, J.J.
Title Influence of multi-step topography on barotropic waves and consequences for numerical modeling Type $loc['typeJournal Article']
Year 2006 Publication Ocean Modelling Abbreviated Journal Ocean Modelling
Volume 14 Issue 1-2 Pages 45-60
Keywords numerical models; ocean mathematical models; topographic waves; double Kelvin waves; continental shelves; shelf waves
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-5003 ISBN Medium
Area Expedition Conference
Funding ONR, NASA Approved $loc['no']
Call Number COAPS @ mfield @ Serial 443
Permanent link to this record
 

 
Author (up) Glazer, R. H.
Title The Influence of Mesoscale Sea Surface Temperature Gradients on Tropical Cyclones Type $loc['typeManuscript']
Year 2014 Publication Abbreviated Journal
Volume Issue Pages
Keywords Air-Sea Interaction; Numerical Modeling; Sea Surface Temperature; Tropical Cyclones; Tropical Meteorology
Abstract
Address Department of Earth, Ocean, and Atmospheric Science
Corporate Author Thesis $loc['Master's thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 161
Permanent link to this record
 

 
Author (up) Gouillon, F
Title Internal Wave Propagation and Numerically Induced Diapycnal Mixing in Oceanic General Circulation Models Type $loc['typeManuscript']
Year 2010 Publication Abbreviated Journal
Volume Issue Pages
Keywords spurious mixing, numerical modeling, internal wave, tide
Abstract Numerical ocean models have become powerful tools for providing a realistic view of the ocean state and for describing ocean processes that are difficult to observe. Recent improvements in model performance focus on simulating realistic ocean interior mixing rates, as ocean mixing is the main physical process that creates water masses and maintains their properties. Below the mixed layer, diapycnal mixing primarily arises from the breaking of internal waves, whose energy is largely supplied by winds and tides. This is particularly true in abyssal regions, where the barotropic tide interacts with rough topography and where high levels of diapycnal mixing have been recorded (e.g., the Hawaiian Archipelago). Many studies have discussed the representation of internal wave generation, propagation, and evolution in ocean numerical models. Expanding on these studies, this work seeks to better understand the representation of internal wave dynamics, energetics, and their associated mixing in several different classes of widely used ocean models (e.g., the HYbrid Coordinate Ocean Model, HYCOM; the Regional Ocean Modeling System, ROMS; and the MIT general circulation model, MITgcm). First, a multi-model study investigates the representation of internal waves for a wide spectrum of numerical choices, such as the horizontal and vertical resolution, the vertical coordinate, and the choice of the numerical advection scheme. Idealized configurations are compared to their corresponding analytical solutions. Some preliminary results of realistic baroclinic tidal simulations are shown for the Gulf of Mexico. Second, the spurious diapycnal mixing that exists in models with fixed vertical coordinates (i.e., geopotential and terrain following) is documented and quantified. This purely numerical error arises because, in fixed-coordinate models, the numerical framework cannot properly maintain the adiabatic properties of an advected water parcel. This unrealistic mixing of water masses can be a source of major error in both regional and global ocean models. We use the tracer flux method to compute the spurious diapycnal diffusivities for both a lockexchange scenario and a propagating internal wave field using all three models. Results for the lock exchange experiments are compared to the results of a recent study. Our results, obtained by using three different model classes, provide a comprehensive analysis of the impact of model resolution choice and numerical framework on the magnitude of the spurious diapycnal mixing and the representation of internal waves.
Address Department of Oceanography
Corporate Author Thesis $loc['Ph.D. thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 571
Permanent link to this record
 

 
Author (up) Guimond, S
Title Tropical Cyclone Inner-Core Dynamics: A Latent Heat Retrieval and Its Effects on Intensity and Structure Change; and the Impacts of Effective Diffusion on the Axisymmetrization Process Type $loc['typeManuscript']
Year 2010 Publication Abbreviated Journal
Volume Issue Pages
Keywords Hurricanes, Doppler Radar, Latent Heat, Axisymmetrization, Diffusion, Numerical Modeling
Abstract Despite the fact that latent heating in cloud systems drives many atmospheric circulations, including tropical cyclones, little is known of its magnitude and structure due in large part to inadequate observations. In this work, a reasonably high-resolution (2 km), four-dimensional airborne Doppler radar retrieval of the latent heat of condensation is presented for rapidly intensifying Hurricane Guillermo (1997). Several advancements in the retrieval algorithm are shown including: (1) analyzing the scheme within the dynamically consistent framework of a numerical model, (2) identifying algorithm sensitivities through the use of ancillary data sources and (3) developing a precipitation budget storage term parameterization. The determination of the saturation state is shown to be an important part of the algorithm for updrafts of ~ 5 m s-1 or less. The uncertainties in the magnitude of the retrieved heating are dominated by errors in the vertical velocity. Using a combination of error propagation and Monte Carlo uncertainty techniques, biases were found to be small, and randomly distributed errors in the heating magnitude were ~16 % for updrafts greater than 5 m s-1 and ~156 % for updrafts of 1 m s- 1. The impact of the retrievals is assessed by inserting the heating into realistic numerical simulations at 2 km resolution and comparing the generated wind structure to the Doppler radar observations of Guillermo. Results show that using the latent heat retrievals outperforms a simulation that relies on a state-of-the-art microphysics scheme (Reisner and Jeffery 2009), in terms of wind speed root-mean-square errors, explained variance and eye/eyewall structure. The incorrect transport of water vapor (a function of the sub-grid model and the numerical approximations to advection) and the restrictions on the magnitude of heat release that ensure the present model's stability are suggested as sources of error in the simulation without the retrievals. Motivated by the latent heat retrievals, the dynamics of vortex axisymmetrization from the perspective of thermal anomalies is investigated using an idealized, non-linear atmospheric model (HIGRAD). Attempts at reproducing the results of previous work (Nolan and Grasso 2003; NG03) revealed a discrepancy with the impacts of purely asymmetric forcing. While NG03 found that purely asymmetric heating led to a negligible, largely negative impact on the vortex intensification, in the present study the impacts of asymmetries are found to have an important, largely positive role. Absolute angular momentum budgets revealed that the essential difference between the present work and that of NG03 was the existence of a significant, axisymmetric secondary circulation in the basic-state vortex used in the HIGRAD simulations. This secondary circulation was larger than that present in NG03's simulations. The spin-up of the vortex caused by the asymmetric thermal anomalies was dominated by the axisymmetric fluxes of angular momentum at all times, indicating fundamentally different evolution of asymmetries in the presence of radial flow. Radial momentum budgets were performed to elucidate the mechanisms responsible for the formation of the physically significant secondary circulation. Results show that explicit (sub-grid) diffusion in the model was producing a gradient wind imbalance, which drives a radial inflow and associated secondary circulation in an attempt to re-gain balance. In addition, the production of vorticity anomalies from the asymmetric heating was found to be sensitive to the eddy diffusivity, with large differences between HIGRAD and the widely used WRF model for the exact same value of this uncertain parameter.
Address Department of Earth, Ocean and Atmospheric Science
Corporate Author Thesis $loc['Ph.D. thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 573
Permanent link to this record
 

 
Author (up) Kvaleberg, E
Title Generation of Cold Core Filaments and Eddies Through Baroclinic Instability on a Continental Shelf Type $loc['typeManuscript']
Year 2004 Publication Abbreviated Journal
Volume Issue Pages
Keywords Eddies, Baroclinic Instability, Filaments, Numerical Modeling, Shelf
Abstract The formation of cold core filaments on an idealized continental shelf is investigated using a numerical model to simulate the ocean's response to surface cooling. A horizontal density gradient forms because of uneven buoyancy loss due to the sloping bottom, and this gradient induces an alongshelf current in thermal wind balance, that in time becomes unstable. As the instabilities grow, filaments, and later eddies, are generated so that dense water near the coast is mixed offshore. Scaling arguments of the filament wavelength indicate that the current is baroclinically unstable, and an analytical model of the frontal expansion with time is in very good agreement with the simulations. This study was inspired by satellite observations of sea surface temperature on the West Florida Shelf during the winter months, in which it is clearly seen that cold core filaments extend from a thermal front. Numerical experiments are therefore designed to allow for reliable comparisons with conditions in this region.
Address Department of Oceanography
Corporate Author Thesis $loc['Ph.D. thesis']
Publisher Florida State University Place of Publication Tallahassee, FL Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 592
Permanent link to this record
 

 
Author (up) Morrison, T.; Dukhovskoy, D. S.; McClean, J.; Gille, S. T.; Chassignet, E.
Title Causes of the anomalous heat flux onto the Greenland continental shelf Type $loc['typeAbstract']
Year 2018 Publication American Geophysical Union Abbreviated Journal AGU
Volume Fall Meeting Issue Pages
Keywords 0726 Ice sheets, CRYOSPHEREDE: 4207 Arctic and Antarctic oceanography, OCEANOGRAPHY: GENERALDE: 4215 Climate and interannual variability, OCEANOGRAPHY: GENERALDE: 4255 Numerical modeling, OCEANOGRAPHY: GENERAL
Abstract On the continental shelf around Greenland, warm-salty Atlantic water at depth fills the deep narrow fjords where Greenland's tidewater glaciers terminate. Changes in the quantity or properties of this water mass starting in the mid 1990s is thought to be largely responsible for increased ocean-driven melting of the Greenland Ice Sheet. Using high-resolution (nominal 0.1-degree) ocean circulation models we cannot accurately resolve small-scale processes on the shelf or within fjords. However, we can assess changes in the flux of heat via Atlantic water onto the continental shelf. To understand the causes of the anomalous heat that has reached the shelf we examine heat content of subtropical gyre water and shifts in the North Atlantic and Atlantic Multidecadal Oscillations.

We compare changes in heat transport in two eddy permitting simulations: a global 0.1 degree (5-7km around Greenland) resolution coupled hindcast (1970-2009) simulation of the Parallel Ocean Program (POP) and a regional 0.08 degree (3-5km around Greenland) resolution coupled HYbrid Coordinate Ocean Model (HYCOM) hindcast (1993-2016) simulation. Both models are coupled to the Los Alamos National Laboratory Community Ice CodE version 4 and forced by atmospheric reanalysis fluxes. In both models we look for processes that could explain the increase in heat; processes that are present in both are likely to be robust causes of warming.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ user @ Serial 1009
Permanent link to this record
 

 
Author (up) Zavala-Hidalgo, J; Pares-Sierra, A; Ochoa, J
Title Seasonal variability of the temperature and heat fluxes in the Gulf of Mexico Type $loc['typeJournal Article']
Year 2002 Publication Atmosfera Abbreviated Journal
Volume 15 Issue 2 Pages 81-104
Keywords Gulf of Mexico; heat fluxes; numerical model; sea surface temperature; seasonal variability
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Funding Approved $loc['no']
Call Number COAPS @ mfield @ Serial 498
Permanent link to this record

2000 Levy Avenue
Building A, Suite 292
Tallahassee, FL 32306-2741
Phone: (850) 644-4581
Fax: (850) 644-4841
contact@coaps.fsu.edu

© 2024 Center for Ocean-Atmospheric Prediction Studies (COAPS), Florida State University

Center for Ocean-Atmospheric Prediction Studies (COAPS)