Variability of spatial-temporal character of ice rain in recent decades

摘要

This study firstly examines fifty three times processes of ice rain chose from the period 1978–2002, defines the incidental region and discusses its character of the spatial-temporal variability in recent decades. The results show the time series of ice rain frequency over the region has a significant trend, with a break point happened in 1990. Then, the number of station that experienced the ice rain and the duration are connected closely, meaning either of them could be used to describe the variability of ice rain. Moreover, through the methods of composite analysis and empirical orthogonal function (EOF), we reveal that the inversion layer is not only the requirement for producing the ice rain, but also it acts as an intensity adjustor for the strength of latter.