摘要
With the development of high-resolution and multi-scale unified numerical model, some of techniques about non-hydrostatic meso-scale numerical weather prediction are addressed. The impact of the vertical coordinate system is one of them. In this paper, based on a WRF (Weather Research and Forecast) model, the impact on the calculation of vertical velocity was studied with different vertical coordinates. The simulation results showed that the calculation of vertical velocity is sensitive to vertical coordinates. It is especially more evident when the resolution increased. Due to the close relationships between vertical velocity and precipitation, the difference of vertical velocity inevitably influences model’s description of precipitation. An ideal experiment exhibits that pressure gradient force computations in the pressure terrain- following coordinate are sensitive to surface pressure.
With the development of high-resolution and multi-scale unified numerical model, some of techniques about non-hydrostatic meso-scale numerical weather prediction are addressed. The impact of the vertical coordinate system is one of them. In this paper, based on a WRF （Weather Research and Forecast） model, the impact on the calculation of vertical velocity was studied with different vertical coordinates. The simulation results showed that the calculation of vertical velocity is sensitive to vertical coordinates. It is especially more evident when the resolution increased. Due to the close relationships between vertical velocity and precipitation, the difference of vertical velocity inevitably influences model＇s description of precipitation. An ideal experiment exhibits that pressure gradient force computations in the pressure terrain-following coordinate are sensitive to surface pressure.
基金
Innovative Research on the Techniques of Numerical Meteorological Forecasting Systems inChina - a National Key Scientific and Technological Project for the 10th Five-year Economic Development Plan(2001BA607B02)
Research on topographic effects by the Chinese Academy of Meteorological Sciences(7048/2002-9y-1)
关键词
数值预报模型
协调系统
运动速度
垂直方向
天气预报
numerical prediction models
coordinate system
vertical velocity
pressure gradient force
