Browsing Applied Mathematics by Author "Waite, Michael L"
Now showing items 1-14 of 14
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An Anisotropic Subgrid-Scale Parameterization for Large-Eddy Simulations of Stratified Turbulence
Khani, Sina; Waite, Michael L (AMS, 2020-10-01)Subgrid-scale (SGS) parameterizations in atmosphere and ocean models are often defined independently in the horizontal and vertical directions because the grid spacing is not the same in these directions (anisotropic ... -
Backscatter in stratified turbulence
Khani, Sina; Waite, Michael L (Elsevier, 2016-11)In this paper, kinetic and potential energy transfers around a spectral test fil ter scale in direct numerical simulations of decaying stratified turbulence are studied in both physical and spectral domains. It is shown ... -
Characteristics of quasistationary near-wall turbulence subjected to strong stable stratification in open-channel flows
Atoufi, Amir; Scott, K. Andrea; Waite, Michael L (American Physical Society, 2020-06-05)Characteristics of near-wall turbulence at quasistationarity under strong wall cooling are studied using direct numerical simulation of open-channel flow. It is shown that if turbulence reaches quasistationarity, then the ... -
Dependence of model energy spectra on vertical resolution
Waite, Michael L (American Meteorological Society, 2016-03)Many high-resolution atmospheric models can reproduce the qualitative shape of the atmospheric kinetic energy spectrum, which has a power-law slope of −3 at large horizontal scales that shallows to approximately −5/3 in ... -
Normal Mode Spectra of Idealized Baroclinic Waves
Ambacher, Matthew R.; Waite, Michael L (AMS, 2020-02-01)Normal modes are used to investigate the contributions of geostrophic vortices and inertia–gravity waves to the energy spectrum of an idealized baroclinic wave simulation. The geostrophic and ageostrophic modal spectra ... -
Prandtl number dependence of stratified turbulence
Legaspi, Jesse D.; Waite, Michael L (Cambridge, 2020-09-21)Stratified turbulence has a horizontally layered structure with quasi-two-dimensional vortices due to buoyancy forces that suppress vertical motion. The Prandtl number Pr quantifies the relative strengths of viscosity ... -
Random forcing of geostrophic motion in rotating stratified turbulence
Waite, Michael L (AIP, 2017-12-29)Random forcing of geostrophic motion is a common approach in idealized simulations of rotating stratified turbulence. Such forcing represents the injection of energy into large-scale balanced motion, and the resulting ... -
Realizing surface driven flows in the primitive equations
Bembenek, Eric; Poulin, Francis J; Waite, Michael L (American Meteorological Society, 2015-05)The surface quasigeostrophic (SQG) model describes flows with surface buoyancy perturbations with no interior quasigeostrophic potential vorticity at small Rossby number Ro and O(1) Burger number, where quasigeostrophic ... -
Resolution Dependence and Subfilter-Scale Motions in Idealized Squall-Line Simulations
Lai, Kwan Tsaan; Waite, Michael L (AMS, 2020-07-08)In this paper, the sensitivity of idealized squall-line simulations to horizontal resolution, subgrid turbulence mixing scheme, and subfilter-scale motion is discussed. Inconsistent results from numerical simulations ... -
Scale-dependent anisotropy in forced stratified turbulence
Lang, Christopher J.; Waite, Michael L (American Physical Society, 2019-04)In stratified turbulence, buoyancy forces inhibit vertical motion and lead to anisotropy over a wide range of length scales, which is characterized by layerwise pancake vortices, thin regions of strong shear, and patches ... -
Short-wave vortex instability in stratified flow
Bovard, Luke; Waite, Michael L (Elsevier, 2016-01)In this paper we investigate a new instability of the Lamb–Chaplygin dipole in a stratified fluid. Through numerical linear stability analysis, a secondary peak in the growth rate emerges at vertical scales about an order ... -
Spectral energy balance in dry convective boundary layers
Sandham, James; Waite, Michael L (Taylor and Francis, 2015-04)Three-dimensional large-eddy simulations (LES) of the convective boundary layer over a domain of approximately 6 km are performed with the UCLA LES model. Simulations are forced with a constant surface heat flux and ... -
Topographically generated internal waves and boundary layer instabilities
Soontiens, Nancy; Stastna, Marek; Waite, Michael L (American Institute of Physics, 2015-08)Flow over topography has been shown to generate finite amplitude internal waves upstream, over the topography and downstream. Such waves can interact with the viscous bottom boundary layer to produce vigorous instabilities. ... -
Wall turbulence response to surface cooling and formation of strongly stable stratified boundary layers
Atoufi, Amir; Scott, K. Andrea; Waite, Michael L (AIP, 2019-08-20)This paper investigates the processes by which stable boundary layers are formed through strong surface cooling imposed on neutrally stratified wall-bounded turbulence using high-resolution direct numerical simulation at ...