Title |
Development of Geometric Moments Based Ellipsoid Model for Extracting Spatio-Temporal Characteristics of Rainfall Field |
Keywords |
rainfall field;extreme rainfall;moment;ellipse;direction of rainfall field;강우장;극치강수량;모멘트;타원;강우이동 |
Abstract |
It has been widely acknowledged that climate system associated with extreme rainfall events was difficult to understand and extreme rainfall simulation in climate model was more difficult. This study developed a new model for extracting rainfall filed associated with extreme events as a way to characterize large scale climate system. Main interests are to derive location, size and direction of the rainfall field and this study developed an algorithm to extract the above characteristics from global climate data set. This study mainly utilized specific humidity and wind vectors driven by NCEP reanalysis data to define the rainfall field. Geometric first and second moments have been extensively employed in defining the rainfall field in selected zone, and an ellipsoid based model were finally introduced. The proposed geometric moments based ellipsoid model works equally well with regularly and irregularly distributed synthetic grid data. Finally, the proposed model was applied to space-time real rain-fall filed. It was found that location, size and direction of the rainfall field was successfully extracted. |