Zeng Qingcun pioneered the "semi-implicit difference method" numerical prediction, which is a commonly used numerical simulation technology in meteorological field, and is used to predict the changing trend of atmospheric circulation, temperature, humidity and other related parameters.
1. Basic principle of "semi-implicit difference method"
Semi-implicit difference method is a numerical solution method based on finite difference method. The basic idea is to discretize the time derivative term (implicit) and the space derivative term (explicit) in the partial differential equation by difference approximation, and then transform them into linear equations to solve. Compared with fully implicit difference method and fully explicit difference method, "semi-implicit difference method" has achieved a good balance between stability and computational efficiency.
2. The characteristics of "semi-implicit difference method"
2. 1 Stability: Because of the implicit difference method, the "semi-implicit difference method" can handle a larger time step, thus improving the stability of numerical simulation.
2.2 Accuracy: Compared with the fully explicit difference method, the "semi-implicit difference method" has higher simulation accuracy for complex phenomena such as turbulence. This is because the implicit time difference is adopted, which can better capture the changes on the long time scale.
2.3 Calculation efficiency: Compared with the full implicit difference method, the semi-implicit difference method reduces the calculation amount and improves the calculation efficiency.
3. The application of "semi-implicit difference method" in numerical prediction.
The "semi-implicit difference method" has been widely used in numerical forecast in meteorological field, mainly in the following aspects:
3. 1 Meteorological model: A meteorological model is a model established by using mathematical and physical principles to describe the laws of atmospheric movement and change. As a numerical solution method, "semi-implicit difference method" is widely used in meteorological models and provides a forecast of future meteorological environment.
3.2 Atmospheric circulation: The semi-implicit difference method can simulate the changing trend of atmospheric circulation, including wind field, pressure field and temperature field. Numerical simulation and prediction of these parameters can provide important basis for weather forecast and climate forecast.
3.3 Meteorological disaster early warning: Through numerical simulation and analysis of meteorological parameters, the "semi-implicit difference method" can give early warning to typhoon, rainstorm and other meteorological disasters, and provide early warning information and decision support for relevant departments and the public.
4. Development trend of semi-implicit difference method
With the continuous progress of computer technology, the application of "semi-implicit difference method" in numerical prediction is also developing and improving. Future development trends mainly include:
4. 1 Accuracy improvement: By improving the difference scheme and introducing more accurate physical parameterization scheme, the simulation accuracy of "semi-implicit difference method" is further improved.
4.2 Efficiency optimization: Combining parallel computing, high-performance computing and other technical means to improve computing efficiency and shorten numerical simulation time.
4.3 Multi-scale expansion: Applying the "semi-implicit difference method" to multi-scale simulation can better simulate local details and large-scale changes on the global scale.
Summary:
As a commonly used numerical prediction method, semi-implicit difference method can simulate the changing trend of atmospheric circulation, temperature and humidity through difference approximation and linear equations. It has advantages in stability, accuracy and calculation efficiency, and is widely used in meteorological model, atmospheric circulation simulation and meteorological disaster early warning. In the future, with the continuous development of technology, the "semi-implicit difference method" will be continuously improved and optimized to improve the simulation accuracy and calculation efficiency, and extended to multi-scale simulation.