Retrieving ice precipitation using a radar snow profiling algorithm: Applications on X-band and C-band weather radar

Weather radar in mountains area is likely to observe snow precipitation, particularly in winter season. Retrieving ice precipitation from radar reflectivity is subject to large uncertainties, due to the variability of the standard Z-R relationship in the ice phase. In this paper, a new algorithm (called hereafter SPA) is proposed for retrieving ice characteristics associated to stratiform clouds, using the vertical profile of reflectivity Z. This algorithm is based on a simplified model of ice particle aggregation. SPA is a profiling algorithm since it helps to invert the vertical profile of Z to deliver the corresponding profiles of various physical parameters of interest: the mean volume diameter (D_m), the intercept parameter N₀*, the ice water content IWC and the precipitation rate R.

A first application of SPA on X-band and C-band weather data is presented using vertical profiles of reflectivity derived from scanning weather radar. The retrieved N₀* profile is therefore used to adjust the Z-R snow relationship. Comparison with rain gauges networks will be presented.