论大气模式的垂直离散(Ⅱ)──垂直离散
ON THE VERTICAL DISCRETIZATION OF ATMOSPHERIC MODELS (Ⅱ) ──VERTICAL DISCRETIZATION
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摘要: 提出了用lnσ等距分层和Tschebyscheff多项式沿垂直方向展开气象要素的方案;并证明:在绝热无耗散且时间和水平方向要素连续的情况,可以在高精度条件下,保证质量和能量守恒,且具有正确的动、位能之间的转换关系。数值计算表明:两方案均有较高的计算精度;在积分静力方程时,位势高度计算误差显著小于EC79方案。Abstract: Two schemes for vertical discretization of the model are proposed,one with equal lna in-terval and the other in terms of Tschebyscheff polynomial.It is proved that in adiabatic and inviscid case if the meteorological elements are continuous in time and horizontal direction the total energy and total mass are conserved in high approximation,and there is a correct conversion between kinetic and total potential energy.Numerical computations show that the schemes both have highaccuracy.For example.in integrating the hydrostatic equation the computational errors of geopotential resulted from the schemes are much less than those resulted from EC79.