Identification of Vertical Profiles of Radar Reflectivity for Hydrological Applications Using an Inverse Method. Part II: Formulation

Abstract

A method of identification of the vertical profile of reflectivity, formulated by the authors in an accompanying paper, is tested through a sensitivity analysis. Two simulated but realistic profiles (with and without brightband effects) are used. The radar features and the statistical parameters involved in this method are allowed to varyaround standard values in order to understand their influence on the results. The main conclusion is that, for a given radar configuration, results of acceptable quality can be obtained with a single adjustment ofthe method for the two types of profiles, which suggests the approach is operationally applicable. To complement this theoretical analysis, actual profiles of reflectivities are studied for two rainfall eventsobserved in the Cevennes region of France. The efficiency of the proposed method is appreciated from a hydrological point of view. A comparison is performed at the basin scale between hourly rainfall intensities, measured with a dense network of rain gauges and radar data. The analysis shows that the introduction of the identification and the correction of the influence of vertical profiles of reflectivity improve the accuracy of rainfall estimates from radar data.