The weather radar component of HyMeX

The HYdrological cycle in the Mediterranean EXperiment (HyMeX) aims at a better understanding and quantification of the hydrological cycle and related processes in the Mediterranean, with emphasis on high-impact weather events and orographic precipitation. A fundamental element that has been missing in past field experiments is nearly simulaneous measurements of the moist inflow as a function of time, height and along-barrier distance with measurements of the precipitation over the orography and the turbulence/microphysical transformations occurring in between. The weather radar component of HyMeX, which will involve a number of research radars and more than 50 operational weather radars throughout Europe, represents the most ambitious field project to date in the endeavor to collect such basic, but hard-to-obtain information, to advance understanding and predictability.

This paper aims to (i) provide a description of the planned radar deployment in southern France, Spain and Italy during the HyMeX 2012 and 2013 special observing periods, (ii) describe the experimental strategies that will be relied upon to document unprecedented details in hydrometeor species, 3D wind vector fields, raindrop spectra, and subsequent surface rainfall patterns over complex terrain and (iii) discuss the synergy between weather radars and other sensors/networks (wind profilers, remote sensing supersites, GPS, aircrafts) to be deployed for the two HyMeX field phases. Examples of advanced real-time radar products available for HyMeX such as “polarimetric” QPE data and 3-D fields of complete wind vectors and hydrometeor species inferred from the analysis of operational data collected during recent major precipitation events in southern France (15 June 2010 flash flood in Draguignan & 6-7 Sept 2010 heavy precipitation event in Ardeche/Gard departments), will also be presented.