摘要
近年来世界上随着几个气象中心的集合预报投入业务 ,标志着业务数值天气预报进入了一个新的纪元。在任何时候大气的真实状态是不知道的 ,只能近似地描述大气 ,所以确切地说 ,天气预报问题应该提为在大气的相空间中合适的概率密度函数随时间的演变。在误差的增长超出线性动力学范畴之外 ,集合预报是预报大气概率密度函数演变唯一可行的方法。可用扰动的产生是集合预报的主要问题之一。沿着预报系统相空间中最不稳定的方向来扰动初始条件是一种方法 ,它是与给定的初始资料相协调确定主要天气类型的最有效的方法。
A new era in operational numerical weather prediction(NWP) began in recent years when the ensemble predictions were performed in some meteorological centers in the world.Since the actual state of the atmosphere at any time is known only approximately,a complete description of the weather prediction problem should be formulated in terms of the time evolution of an appropriate probability density function in the atmosphere′s phase space.Ensemble forecasting appears to be the only feasible method to predict the evolution of the atmospheric probability density function beyond the range in which error growth can be described by linearized dynamics.The generation of effective perturbation is one of the major problems in ensemble forecasting.Perturbing the initial conditions along the most unstable directions of the phase space of the system is a technique which may be most effective for determining the principal weather types consistent with given initial data.The singular vectors and Chinese ensemble prediction systems were described briefly.
出处
《气象》
CSCD
北大核心
2000年第6期21-25,共5页
Meteorological Monthly
关键词
集合预报
奇异向量法
准确率
数值天气预报
ensemble prediction singular vector weather forecast probability density function
