Gravity wave breaking in two and three dimensions: 2. Three-dimensional evolution and instability structure

1994 ◽  
Vol 99 (D4) ◽  
pp. 8109 ◽  
Author(s):  
David C. Fritts ◽  
Joseph R. Isler ◽  
Øyvind Andreassen
Keyword(s):  
Gravity Wave ◽  
Wave Breaking ◽  
Three Dimensional ◽  
Three Dimensions

Gravity wave breaking in two and three dimensions: 3. Vortex breakdown and transition to isotropy

1994 ◽  
Vol 99 (D4) ◽  
pp. 8125 ◽  
Author(s):  
Joseph R. Isler ◽  
David C. Fritts ◽  
Øyvind Andreassen ◽  
Carl Erik Wasberg
Keyword(s):  
Gravity Wave ◽  
Wave Breaking ◽  
Vortex Breakdown ◽  
Three Dimensions

Direct numerical simulation of a breaking inertia–gravity wave

2013 ◽  
Vol 722 ◽  
pp. 424-436 ◽  
Author(s):  
S. Remmler ◽  
M. D. Fruman ◽  
S. Hickel
Keyword(s):  
Gravity Wave ◽  
Wave Breaking ◽  
Middle Atmosphere ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Domain Size ◽  
Boussinesq Equations ◽  
Two Dimensional ◽  
Instability Modes

AbstractWe have performed fully resolved three-dimensional numerical simulations of a statically unstable monochromatic inertia–gravity wave using the Boussinesq equations on an $f$-plane with constant stratification. The chosen parameters represent a gravity wave with almost vertical direction of propagation and a wavelength of 3 km breaking in the middle atmosphere. We initialized the simulation with a statically unstable gravity wave perturbed by its leading transverse normal mode and the leading instability modes of the time-dependent wave breaking in a two-dimensional space. The wave was simulated for approximately 16 h, which is twice the wave period. After the first breaking triggered by the imposed perturbation, two secondary breaking events are observed. Similarities and differences between the three-dimensional and previous two-dimensional solutions of the problem and effects of domain size and initial perturbations are discussed.

scholarly journals Dynamics of Orographic Gravity Waves Observed in the Mesosphere over the Auckland Islands during the Deep Propagating Gravity Wave Experiment (DEEPWAVE)

2016 ◽  
Vol 73 (10) ◽  
pp. 3855-3876 ◽  
Author(s):  
Stephen D. Eckermann ◽  
Dave Broutman ◽  
Jun Ma ◽  
James D. Doyle ◽  
Pierre-Dominique Pautet ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Gravity Waves ◽  
Wave Breaking ◽  
Large Amplitude ◽  
Middle Atmosphere ◽  
Three Dimensional ◽  
Surface Flow ◽  
Heating Rates ◽  
Wave Fields ◽  
Wave Experiment

Abstract On 14 July 2014 during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), aircraft remote sensing instruments detected large-amplitude gravity wave oscillations within mesospheric airglow and sodium layers at altitudes z ~ 78–83 km downstream of the Auckland Islands, located ~1000 km south of Christchurch, New Zealand. A high-altitude reanalysis and a three-dimensional Fourier gravity wave model are used to investigate the dynamics of this event. At 0700 UTC when the first observations were made, surface flow across the islands’ terrain generated linear three-dimensional wave fields that propagated rapidly to z ~ 78 km, where intense breaking occurred in a narrow layer beneath a zero-wind region at z ~ 83 km. In the following hours, the altitude of weak winds descended under the influence of a large-amplitude migrating semidiurnal tide, leading to intense breaking of these wave fields in subsequent observations starting at 1000 UTC. The linear Fourier model constrained by upstream reanalysis reproduces the salient aspects of observed wave fields, including horizontal wavelengths, phase orientations, temperature and vertical displacement amplitudes, heights and locations of incipient wave breaking, and momentum fluxes. Wave breaking has huge effects on local circulations, with inferred layer-averaged westward flow accelerations of ~350 m s−1 h−1 and dynamical heating rates of ~8 K h−1, supporting recent speculation of important impacts of orographic gravity waves from subantarctic islands on the mean circulation and climate of the middle atmosphere during austral winter.

Gravity wave breaking in two and three dimensions: 1. Model description and comparison of two-dimensional evolutions

1994 ◽  
Vol 99 (D4) ◽  
pp. 8095 ◽  
Author(s):  
Øyvind Andreassen ◽  
Carl Erik Wasberg ◽  
David C. Fritts ◽  
Joseph R. Isler
Keyword(s):  
Gravity Wave ◽  
Wave Breaking ◽  
Three Dimensions ◽  
Model Description ◽  
Two Dimensional

Validation of Large-Eddy Simulation Methods for Gravity Wave Breaking

2015 ◽  
Vol 72 (9) ◽  
pp. 3537-3562 ◽  
Author(s):  
Sebastian Remmler ◽  
Stefan Hickel ◽  
Mark D. Fruman ◽  
Ulrich Achatz
Keyword(s):  
Large Eddy Simulation ◽  
Gravity Wave ◽  
Wave Breaking ◽  
Three Dimensional ◽  
Small Scale ◽  
Turbulence Parameterization ◽  
Eddy Simulation ◽  
Numerical Studies ◽  
Large Eddy ◽  
Scale Turbulence

Abstract To reduce the computational costs of numerical studies of gravity wave breaking in the atmosphere, the grid resolution has to be reduced as much as possible. Insufficient resolution of small-scale turbulence demands a proper turbulence parameterization in the framework of a large-eddy simulation (LES). The authors validate three different LES methods—the adaptive local deconvolution method (ALDM), the dynamic Smagorinsky method (DSM), and a naïve central discretization without turbulence parameterization (CDS4)—for three different cases of the breaking of well-defined monochromatic gravity waves. For ALDM, a modification of the numerical flux functions is developed that significantly improves the simulation results in the case of a temporarily very smooth velocity field. The test cases include an unstable and a stable inertia–gravity wave as well as an unstable high-frequency gravity wave. All simulations are carried out both in three-dimensional domains and in two-dimensional domains in which the velocity and vorticity fields are three-dimensional (so-called 2.5D simulations). The results obtained with ALDM and DSM are generally in good agreement with the reference direct numerical simulations as long as the resolution in the direction of the wave vector is sufficiently high. The resolution in the other directions has a weaker influence on the results. The simulations without turbulence parameterization are only successful if the resolution is high and the level of turbulence is comparatively low.

A Theoretical and Numerical Study of Urban Heat Island–Induced Circulation and Convection

2008 ◽  
Vol 65 (6) ◽  
pp. 1859-1877 ◽  
Author(s):  
Ji-Young Han ◽  
Jong-Jin Baik
Keyword(s):  
Urban Heat Island ◽  
Gravity Wave ◽  
Vertical Velocity ◽  
Three Dimensional ◽  
Internal Gravity Wave ◽  
Three Dimensions ◽  
Heat Island ◽  
Upward Motion ◽  
Additional Dimension ◽  
Urban Heat

Abstract Urban heat island–induced circulation and convection in three dimensions are investigated theoretically and numerically in the context of the response of a stably stratified uniform flow to specified low-level heating that represents an urban heat island. In a linear, theoretical part of the investigation, an analytic solution for the perturbation vertical velocity in a three-dimensional, time-dependent, hydrostatic, nonrotating, inviscid, Boussinesq airflow system is obtained. The solution reveals a typical internal gravity wave field, including low-level upward motion downwind of the heating center. Precipitation enhancement observed downwind of urban areas may be partly due to this downwind upward motion. The comparison of two- and three-dimensional flow fields indicates that the dispersion of gravity wave energy into an additional dimension results in a faster approach to a quasi-steady state and a weaker quasi-steady flow well above the concentrated heating region in three dimensions. In a nonlinear, numerical modeling part of the investigation, extensive dry and moist simulations using a nonhydrostatic, compressible model with advanced physical parameterizations [Advanced Regional Prediction System (ARPS)] are performed. While the maximum perturbation vertical velocity in the linear internal gravity wave field exists in the downwind region close to the heating center, the maximum updraft in three-dimensional dry simulations propagates downwind and then becomes quasi stationary. In three-dimensional moist simulations, it is demonstrated that the downwind upward motion induced by an urban heat island can initiate moist convection and result in downwind precipitation. The cloud induced by the downwind upward motion grows rapidly to become deep convective clouds. Heavy rainfalls are localized in a region not far from the heating center by a convective precipitating system that is nearly stationary. The differences in results between two and three dimensions are explained by the presence of (moist) convergence in an additional dimension. The numerical simulation results indicate that the intensity and horizontal structure of the urban heat island affect those of circulation and convection and hence the distribution of surface precipitation.

Frequency downshift in three-dimensional wave trains in a deep basin

1997 ◽  
Vol 352 ◽  
pp. 359-373 ◽  
Author(s):  
KARSTEN TRULSEN ◽  
KRISTIAN B. DYSTHE
Keyword(s):  
Gravity Waves ◽  
Deep Water ◽  
Wave Breaking ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Deep Basin ◽  
Weakly Nonlinear ◽  
Wave Trains ◽  
Dimensional Wave

The conservative evolution of weakly nonlinear narrow-banded gravity waves in deep water is investigated numerically with a modified nonlinear Schrödinger equation, for application to wide wave tanks. When the evolution is constrained to two dimensions, no permanent shift of the peak of the spectrum is observed. In three dimensions, allowing for oblique sideband perturbations, the peak of the spectrum is permanently downshifted. Dissipation or wave breaking may therefore not be necessary to produce a permanent downshift. The emergence of a standing wave across the tank is also predicted.

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