The Bollène-2002 experiment: evaluation of processing strategies for radar QPE in the Cévennes-Vivarais region
The Bollène 2002 experiment was designed with Météo-France to test the relevance of a volume-scanning strategy for both hydrological and meteorological applications of weather radar in the Cévennes-Vivarais region, a mountainous region in Southern France prone to intense rain events. The Bollène S-band weather radar belonging to the French ARAMIS radar network was used for this purpose.
Innovative algorithms are developed including: (1) the long-term testing of the transmitter-receiver stability using ground clutter, (2) a dynamical ground clutter identification technique based on the pulse-to-pulse reflectivity variability, (2) a coupled procedure to determine both an automatic separation between convective and stratiform regions and vertical profiles of reflectivity (VPR) conditional on rain types, and (3) a procedure based on a hydrological criterion for estimating rain rates at ground level as a combination of reflectivity measurements at the various elevation angles. The use of Z-R relationships conditional on rain types is also considered.
Several radar data processing strategies based both on static and adaptative algorithms are implemented and co-evaluated with respect to rainfall products derived from the OHM-CV rain gauge networks. The performance and merits (robustness versus accuracy) of the different strategies are detailed for a set of five intense and/or long lasting rain events with contrasted spatial structures.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020