摘要: Recent extreme weather events have demonstrated vividly that the nation's human211and economic resources are increasingly sensitive to a wide variety of weather 211phenomena. Improved quantitative precipitation forecasts (QPF) a... 展开 Recent extreme weather events have demonstrated vividly that the nation's human211and economic resources are increasingly sensitive to a wide variety of weather 211phenomena. Improved quantitative precipitation forecasts (QPF) are the key to 211reducing the loss of life and property noted in the opening paragraph. The 211purpose of this document is to provide the scientific rationale and justification 211for a five-year research plan for the assimilation of meteorological observations 211into numerical weather prediction models. In the broadest sense, meteorological 211data assimilation is partly the incorporation of atmopsheric measurmeents into 211computer models that predict atmospheric behavior and partly the accommodation of 211such models to a set of observations. The goal of data assimilation is to produce 211a regular, physically consistent, four-dimensional representation of the 211atmosphere from a heterogeneous array of in situ and remote instruments which 211sample imperfectly and irregularly in space and time. 收起