Front speed simulation with a hyperbolic model of atmospheric dynamics

International Conference and Early Career Scientists School on Environmental Observations, Modeling and Information Systems: ENVIROMIS-2018

生态环境科学;计算机科学

Yudin, M.S.^1

Institute of Computational Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, Russia^1

关键词: Artificial compressibility;    Atmospheric dynamics;    Atmospheric fronts;    Compressible Navier-Stokes equations;    Dynamic pressures;    Empirical formulas;    Governing equations;    Irregular terrain;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/211/1/012020/pdf
DOI  :  10.1088/1755-1315/211/1/012020

来源: IOP

【 摘 要 】

In this paper the front speed is simulated with a non-hydrostatic finite-element model of atmospheric dynamics. The model is based on the compressible Navier-Stokes equations in two dimensions. Artificial compressibility is introduced into the model in order to make the governing equations hyperbolic. Two tests of the model on different spatial scales are considered: the propagation of a mesoscale atmospheric gravity current (cold front) over flat terrain and the motion of a small scale coastal flow over irregular terrain. In the first test the calculated values of the simulation are compared with an empirical formula first introduced by T. von Karman and later developed for atmospheric fronts by many authors. In the second test, the model is applied to simulating the dynamic pressure effects caused by changes in roughness and interaction of the flow with the non-homogeneous terrain. For this purpose, we consider flow over a low hill at a coastal site. Both model simulation results are compared with available observations and simulations performed by other authors. In general, good agreement between the results of the test calculations and the theory has been obtained.