A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model

2009 ◽  
Vol 22 (11) ◽  
pp. 2834-2849 ◽  
Author(s):  
Mario A. Lopez ◽  
Dennis L. Hartmann ◽  
Peter N. Blossey ◽  
Robert Wood ◽  
Christopher S. Bretherton ◽  
...  
Keyword(s):  
Rain Rate ◽  
Strong Dependence ◽  
Three Dimensional ◽  
Longwave Radiation ◽  
Physical Parameters ◽  
Model Parameters ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Cloud Resolving Model ◽  
Upper Level

Abstract A methodology is described for testing the simulation of tropical convective clouds by models through comparison with observations of clouds and precipitation from earth-orbiting satellites. Clouds are divided into categories that represent convective cores: moderately thick anvil clouds and thin high clouds. Fractional abundances of these clouds are computed as a function of rain rate. A three-dimensional model is forced with steady forcing characteristics of tropical Pacific convective regions, and the model clouds are compared with satellite observations for the same regions. The model produces a good simulation of the relationship between the precipitation rate and optically thick cold clouds that represent convective cores. The observations show large abundances of anvil cloud with a strong dependence on rain rate, but the model produces too little anvil cloud by a factor of about 4 and with a very weak dependence on the rain rate. The observations also show probability density functions for outgoing longwave radiation (OLR) and albedo with maxima that correspond to extended upper-level cold clouds, whereas the model does not. The sensitivity of the anvil cloud simulation to model parameters is explored using a two-dimensional model. Both cloud physical parameters and mean wind shear effects are investigated. The simulation of anvil cloud can be improved while maintaining a good simulation of optically thick cloud by adjusting the cloud physics parameters in the model to produce more ice cloud and less liquid water cloud.

scholarly journals Cloud-Resolving Model Simulations of KWAJEX: Model Sensitivities and Comparisons with Satellite and Radar Observations

2007 ◽  
Vol 64 (5) ◽  
pp. 1488-1508 ◽  
Author(s):  
Peter N. Blossey ◽  
Christopher S. Bretherton ◽  
Jasmine Cetrone ◽  
Marat Kharoutdinov
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Longwave Radiation ◽  
Radiative Fluxes ◽  
Model Simulations ◽  
Time Period ◽  
Ground Validation ◽  
Cloud Resolving Model ◽  
Sensitivity Studies ◽  
Upper Level

Abstract Three-dimensional cloud-resolving model simulations of a mesoscale region around Kwajalein Island during the Kwajalein Experiment (KWAJEX) are performed. Using observed winds along with surface and large-scale thermodynamic forcings, the model tracks the observed mean thermodynamic soundings without thermodynamic nudging during 52-day simulations spanning the whole experiment time period, 24 July–14 September 1999. Detailed comparisons of the results with cloud and precipitation observations, including radar reflectivities from the Kwajalein ground validation radar and International Satellite Cloud Climatology Project (ISCCP) cloud amounts and radiative fluxes, reveal the biases and sensitivities of the model’s simulated clouds. The amount and optical depth of high cloud are underpredicted by the model during less rainy periods, leading to excessive outgoing longwave radiation (OLR) and insufficient albedo. The simulated radar reflectivities tend to be excessive, especially in the upper troposphere, suggesting that simulated high clouds are precipitating large hydrometeors too efficiently. Occasionally, large-scale advective forcing errors also seem to contribute to upper-level cloud and relative humidity biases. An extensive suite of sensitivity studies to different microphysical and radiative parameterizations is performed, with surprisingly little impact on the results in most cases.

Dynamics Simulation of Large Tower Structure Lifting Process Based on CABLE Modeling

2014 ◽  
Vol 533 ◽  
pp. 145-153
Author(s):  
Hong Zhi Zhang ◽  
Xuan Yu Sheng
Keyword(s):  
Steel Wire ◽  
Three Dimensional ◽  
Wire Rope ◽  
Dynamics Simulation ◽  
Physical Parameters ◽  
Dimensional Model ◽  
Analysis Model ◽  
Three Dimensional Model ◽  
Tower Structure ◽  
Eccentric Structure

In this paper, three-dimensional model of the flexible steel wire rope was established by using CABLE software in CATIA software. After defining the physical parameters of the steel wire rope, the dynamics analysis model of wire rope was established in motion workbench. Further fully model was assembled and simulated including cranes, tower, ground in motion workbench. Finally, we obtained hoisting structure of the trajectory curve, dynamic response, eccentric structure, flipping, etc., as well as interference with the surrounding objects.

Three-Dimensional Simulation of the Influences of Operational Parameters on Stability of Formation-Cement Sheath-Casing Combination

2020 ◽  
Vol 980 ◽  
pp. 525-546
Author(s):  
Yong Wen Yuan ◽  
Yan Jun Cheng ◽  
Jin Xin Zhu ◽  
Liu Yi Li
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Physical Parameters ◽  
Dimensional Model ◽  
Operational Parameters ◽  
Three Dimensional Model ◽  
Cement Sheath ◽  
The Stability ◽  
Casing Pressure

At present, most of the studies of the stability of the formation-cement sheath-casing combination have been mainly based on the plane, and the three-dimensional model established is only one example. There is no systematic study of the influence of physical parameters and process parameters on the stability of the combined body under the three-dimensional model and the action of triaxial crustal stress. Through the establishment of three-dimensional formation-cement sheath-casing linear elastic combination model, we can study the influence of operational parameters (cement sheath pressure, casing cross section pressure, inner casing pressure, ellipticity of borehole, centrality of casing, thickness of cement sheath) by the two interfaces’ Von Mises stress and the total displacement of the combination body. It is pointed out that the pressure of cement sheath, and casing cross section pressure have no effect on the stability of formation, cement sheath and casing; The higher the ellipticity of the borehole, the eccentricity of the casing (position 1, 2) and the thickness of the cement sheath, the higher the stability of the second interface of the cementing; The higher the inner casing pressure and the eccentricity of the casing(position 3), the lower the stability of the second interface of the cementing; The higher the eccentricity of the casing (position 2,3) and the thickness of the cement sheath, the higher the stability of the first interface of the cementing; The higher the inner casing pressure, the eccentricity of the casing (position 1) and the ellipticity of the borehole, the lower the stability of the first interface of the cementing; The higher the eccentricity of the casing (position 2,3) and thickness of the cement sheath, the higher the stability of the casing; The higher the inner casing pressure, the ellipticity of the borehole and the eccentricity of the casing(position 1), the lower the stability of the casing. Through this study, according to the formation stress, the formation physical parameters (elastic modulus, Poisson's ratio, density), optimize the operational parameters, ensure the long-term integrity of the combination.

Three-Dimensional Model for Virtual Surgical Simulation, during Complex Skull Base Surgery and Aneurysm Surgery

Skull Base ◽  
2008 ◽  
Vol 18 (S 01) ◽  
Author(s):  
Akio Morita ◽  
Toshikazu Kimura ◽  
Shigeo Sora ◽  
Kengo Nishimura ◽  
Hisayuki Sugiyama ◽  
...  
Keyword(s):  
Skull Base ◽  
Surgical Simulation ◽  
Skull Base Surgery ◽  
Three Dimensional ◽  
Aneurysm Surgery ◽  
Dimensional Model ◽  
Three Dimensional Model
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