An objective analysis algorithm based on the variational method

In meteorological operations, station data are often needed to be transformed to the regular grid with requirements of the gridded field being both accurate and smooth. Due to the contradiction between accuracy and smoothness, the existing objective analysis methods are very difficult to achieve the above requirements. In this paper, based on the variational method, by introducing accuracy and smoothness into a cost function of the gridded field, the optimal objective analysis results can be obtained by solving the minimum value of the cost function. The objective analysis of precipitation examples show that both accurate and smooth requirements can be met by using the variational objective analysis methods.