Global convection modelling
نویسندگان
چکیده
Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU Abstract In global models of the atmosphere convection is parameterised, since the typical scale of this process is smaller than the model resolution. Here we address some of the uncertainties arising from the selection of different algorithms to simulate this process. Four different parameterisations for atmospheric convection, all used in state-of-the-5 art models, are implemented in the model system ECHAM5/MESSy for a consistent inter-comparison and evaluation against observations. Relatively large differences are found in the simulated precipitation patterns, whereas simulated water vapour columns distributions are quite similar and close to observations. The effects on the hydrological cycle and on the simulated meteorological conditions are discussed.
منابع مشابه
Global maximum norm parameter-uniform numerical method for a singularly perturbed convection-diffusion problem with discontinuous convection coefficient
A singularly perturbed convection-diffusion problem, with a discontinuous convection coefficient and a singular perturbation parameter ε, is examined. Due to the discontinuity an interior layer appears in the solution. A finite difference method is constructed for solving this problem, which generates ε-uniformly convergent numerical approximations to the solution. The method uses a piecewise u...
متن کاملGlobal Stability for Thermal Convection in a Couple Stress Fluid Saturating a Porous Medium with Temperature-Pressure Dependent Viscosity: Galerkin Method
A global nonlinear stability analysis is performed for a couple-stress fluid layer heated from below saturating a porous medium with temperature-pressure dependent viscosity for different conducting boundary systems. Here, the global nonlinear stability threshold for convection is exactly the same as the linear instability boundary. This optimal result is important because it shows that lineari...
متن کاملA hierarchical mesh refinement technique for global 3-D spherical mantle convection modelling
A method for incorporating multi-resolution capabilities within pre-existing global 3-D spherical mantle convection codes is presented. The method, which we term “geometric multigrid refinement”, is based upon the application of a multigrid solver on non-uniform, structured grids and allows for the incorporation of local high-resolution grids within global models. Validation tests demonstrate t...
متن کاملLightning and convection parameterisations – uncertainties in global modelling
The simulation of convection, lightning and consequent NO x emissions with global atmospheric chemistry models is associated with large uncertainties since these processes are heavily parameterised. Each parameterisation by itself has deficiencies and the combination of these substantially increases the uncertainties compared to the individual parameterisations. In this study several combinatio...
متن کاملHeat and Mass Transfer
Why heat and mass transfer ................................................................................................................................1 Fundamentals of heat transfer (what is it) ..........................................................................................................2 Thermodynamics of heat transfer ............................................................
متن کامل