The study and applications of photochemical-dynamical gravity wave model I

2002 ◽  
Vol 45 (S1) ◽  
pp. 167-174
Author(s):  
Jiyao Xu ◽  
Ruiping Ma ◽  
A. K. Smith
Keyword(s):  
Gravity Wave ◽  
Wave Model

scholarly journals Interpretation of ground-based radiometric observations in terms of a gravity wave model

1990 ◽  
Vol 95 (D6) ◽  
pp. 7637 ◽  
Author(s):  
F. G. Canavero ◽  
F. Einaudi ◽  
E. R. Westwater ◽  
M. J. Falls ◽  
J. A. Schroeder ◽  
...  
Keyword(s):  
Gravity Wave ◽  
Wave Model

Towards transient subgrid-scale gravity wave representation in atmospheric models. Part II: Wave intermittency simulated with convective sources

2020 ◽  
Author(s):  
Young-Ha Kim ◽  
Gergely Bölöni ◽  
Sebastian Borchert ◽  
Hye-Yeong Chun ◽  
Ulrich Achatz
Keyword(s):  
Gravity Wave ◽  
Wave Model ◽  
Companion Paper ◽  
Tropical Convection ◽  
Subgrid Scale ◽  
Mean Flow ◽  
Flow Interactions ◽  
Log Normal ◽  
Convection Parameterization ◽  
The Tropics

AbstractIn a companion paper, the Multi-Scale Gravity-Wave Model (MS-GWaM) has been introduced and its application to a global model as a transient subgrid-scale parameterization has been described. This paper focuses on the examination of intermittency of gravity waves (GWs) modeled by MS-GWaM. To introduce the variability and intermittency in wave sources, convective GW sources are formulated, using diabatic heating diagnosed by the convection parameterization, and they are coupled to MS-GWaM in addition to a flow-independent source in the extratropics accounting for GWs due neither to convection nor to orography. The probability density function (PDF) and Gini index for GWpseudomomentum fluxes are assessed to investigate the intermittency. Both are similar to those from observations in the lower stratosphere. The intermittency of GWs over tropical convection is quite high and found not to change much in the vertical. In the extratropics, where non-convective GWs dominate, the intermittency is lower than (comparable to) that in the tropics in the stratosphere (mesosphere), exhibiting a gradual increase with altitude. The PDFs in these latitudes seem to be close to the log-normal distributions. Effects of transient GW-mean-flow interactions on the simulated GWintermittency are assessed by performing additional simulations using the steady-state assumption in the GW parameterization. The intermittency of parameterized GWs over tropical convection is found to be overestimated by the assumption, whereas in the extratropics it is largely underrepresented. Explanation and discussion of these effects are included.

Analytical Solution of the Classical Dam-Break Problem for the Gravity Wave–Model Equations

2016 ◽  
Vol 142 (5) ◽  
pp. 06016003 ◽  
Author(s):  
Ricardo Martins ◽  
Jorge Leandro ◽  
Slobodan Djordjević
Keyword(s):  
Analytical Solution ◽  
Gravity Wave ◽  
Wave Model ◽  
Dam Break ◽  
Model Equations

Intermittency of gravity waves modelled by a transient gravity-wave parametrization coupled with convective sources

2020 ◽  
Author(s):  
Young-Ha Kim ◽  
Gergely Bölöni ◽  
Sebastian Borchert ◽  
Hye-Yeong Chun ◽  
Ulrich Achatz
Keyword(s):  
Steady State ◽  
Gravity Wave ◽  
Gravity Waves ◽  
Control Experiment ◽  
Wave Model ◽  
Multi Scale ◽  
Steady State Assumption ◽  
The Tropics ◽  
The Waves ◽  
State Assumption

<p class="Normal tm5"><span class="tm6">The intermittency of gravity waves (GWs) is investigated using Multi-Scale Gravity Wave Model (MS-GWaM) implemented in the upper-atmosphere extension of ICON model. The intermittency of GWs is originated from that of wave sources but altered during propagation of the waves. Conventional GW parametrization (GWP), which diagnoses vertical profiles of GW properties under the steady-state assumption, can take into account the source intermittency if the GWP employs flow-dependent sources, while it cannot present the change of intermittency by transient evolutions of GWs. MS-GWaM is a prognostic model that explicitly solves the evolution of positions of waves (as well as their wavenumbers and amplitudes) in time and thus capable of describing the intermittency change. In order to include the source intermittency and variability, we couple the convective source, as diagnosed by subgrid-scale cumulus parametrization in ICON, to MS-GWaM, based on an analytic formulation of GW response to this source. In addition to this, a spatio-temporally uniform, persistent source is prescribed in the extratropics to take into account other non-orographic sources. Orographic sources are currently not used. The GW intermittency is measured by the Gini index, and is found to be quite high in the tropics, compared to that in the extratropics. In both regions, the index has similar values to those obtained from superpressure balloon observations reported in previous studies. A control experiment is performed using GWP based on the steady-state assumption, but coupled to the same wave sources, to assess the effects of transient modelling using MS-GWaM on the simulated intermittency. From comparison to the control experiment, the intermittency is found to increase largely for GWs from the uniform source but to decrease for convective GWs by the transient modelling.</span></p>

scholarly journals THE EXACT SOLUTION OF THE HIGHEST WAVE DERIVED FROM A UNIVERSAL WAVE MODEL

1984 ◽  
Vol 1 (19) ◽  
pp. 70
Author(s):  
Yang Yih Chen ◽  
Frederick L.W. Tang
Keyword(s):  
Exact Solution ◽  
Solitary Wave ◽  
Gravity Wave ◽  
Wave Height ◽  
Water Depth ◽  
Series Solution ◽  
Wave Model ◽  
Finite Depth

The solitary wave is first established in this paper by extending the series solution of periodic gravity wave as the wavelength approaches to infinite. Then, the highest gravity wave of permanent type in finite depth of water is immediately analyzed. The maximum ratio of wave height to water depth is obtained as 0.85465')..., and the angle at the crest for the considered highest wave is estimated to be 90°.

scholarly journals Assessing the Analytical Solution of One-Dimensional Gravity Wave Model Equations Using Dam-Break Experimental Measurements

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1261 ◽  
Author(s):  
Wenjun Liu ◽  
Bo Wang ◽  
Yunliang Chen ◽  
Chao Wu ◽  
Xin Liu
Keyword(s):  
Gravity Wave ◽  
Water Depth ◽  
Wave Model ◽  
Discontinuity Point ◽  
Weak Discontinuity ◽  
Dam Break ◽  
Experimental Results ◽  
Hydraulic Parameters ◽  
One Dimensional ◽  
Dimensional Gravity

The one-dimensional gravity wave model (GWM) is the result of ignoring the convection term in the Saint-Venant Equations (SVEs), and has the characteristics of fast numerical calculation and low stability requirements. To study its performances and limitations in 1D dam-break flood, this paper verifies the model using a dam-break experiment. The experiment was carried out in a large-scale flume with depth ratios (initial downstream water depth divided by upstream water depth) divided into 0 and 0.1~0.4. The data were collected by image processing technology, and the hydraulic parameters, such as water depth, flow discharge, and wave velocity, were selected for comparison. The experimental results show that the 1D GWM performs an area with constant hydraulic parameters, which is quite different from the experimental results in the dry downstream case. For a depth ratio of 0.1, the second weak discontinuity point, which is connected to the steady zone in the 1D GWM, moves upstream, which is contrary to the experimental situation. For depth ratios of 0.2~0.4, the moving velocity of the second weak discontinuity point is faster than the experimental value, while the velocity of the shock wave is slower. However, as the water depth ratio increases, the hydraulic parameters calculated by 1D GWM in the steady zone gradually approach the experimental value.

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