套网格预报中几种边界条件的试验

EXPERIMENTS WITH SEVERAL TYPES OF BOUNDARY CONDITIONS IN NESTED GRID PREDICTION

摘要:

采用国家气象中心五层原始方程业务模式,用单向自嵌套方法,对常用的几种侧边界条件进行了对比试验。结果表明：加密网格可以改善预报效果,在试验的几种边界处理方案中,以Davies方案的效果最好,不需要采用其他技术处理,就能使边界附近不产生扰动,分析的等值线光滑,计算稳定性好,可以便业务预报更加可靠,效果更加理想。

关键词:套网格模式;边界条件;数值预报

Abstract:

A five-level primitive equation operational model developed by the US NMC is used in control experimenting with several types of lateral boundary conditions commonly used in terms of the one-way automatic nesting method.Results show that the intensive grid scheme can improve the accuracy and,of the boundary-handling schemes,Davies technique is optimal that causes no disturbance in the vicinity of the boundary and produces smooth isolines and high stability without the help of other treatment.The scheme is useful in making operational prediction more accurate.

Key words:nested grid model;boundary conditions;numerical weather prediction