误差扣除法在云南中尺度数值模式中对气压梯度力的计算试验

Experiments on Computing Pressure Gradient Force of Error Subtraction Scheme in Yunnan Mesoscale Numerical Model

使用云南中尺度数值预报试验模式[1] ,引入实际地形 ,选用静力扣除格式、回插格式、局地等温格式、经典修正格式以及模式中原计算格式 (Corby格式 )等 5种计算格式计算气压梯度力 ,对气压梯度力的误差扣除法进行了模拟试验。比较了这 5种格式在有、无误差扣除时的模拟结果之后 ,发现误差扣除法与上述格式结合使用时 ,均能够不同程度地提高预报效果 ,尤其是在与经典修正格式结合使用以后 ,预报效果进一步改善 。

A new method, named as error subtraction scheme, is introduced into Yunnan mesoscale numerical forecasting experimental model to compute the pressure gradient force for high and steep topographic areas. The modelling results of the five schemes with and without the error subtraction scheme are compared with one another. It is found that the modelling results are not perfect enough when they are directly used in three examples. However, when five formulas are used with the error subtraction scheme, the results are all remarkable improved to different extent, and the one using the revised classical scheme is more successful.