Rain and snow remote sensing in high mountain regions for improved water resources and hydrological risk assessment

Laboratoire de rattachement : IGE (LTHE), équipe HMCIS

Encadrant : Guy Delrieu (guy.delrieu univ-grenoble-alpes.fr)

Téléphone : 04.76.82.50.53

Co-Encadrant : Brice Boudevillain (brice.boudevillain univ-grenoble-alpes.fr)

Mots clés : hydrometeorology, weather radar, quantitative precipitation estimation

Contexte et objectifs de la mission de stage :

The M2R topic is proposed within a project aimed at developing advanced methods for snow and rain estimation in high mountain regions. It relies on a unique observation system composed of two X-band Doppler and polarimetric weather radars installed over an altitude gradient (200 and 1900 m ASL) in the region of Grenoble. The project is carried out by LTHE/HMCIS in collaboration with Météo-France and the Global Precipitation Measurement science team (NASA).

The first objective is to develop the so-called Mountain Reference Technique which fully exploits the undesired radar mountain returns for determining the detection domain of the radars, performing the radar calibration and estimating path-integrated attenuations between the radar and mountain targets, a critical information for attenuation correction.

The second objective is the characterization of the 4D structure of precipitation within the Grenoble intermount basin using volumetric multi-parameter radar measurements, as well as hydrometeor size and speed distribution sensors at ground level. Focus is given on the vertical position of the 0°C isotherm and the extension of the melting layer since they determine the rain/snow occurrence at ground level.

The third objective is the quantitative assessment of the rain/snow estimates at ground level. Several aspects are studied, including (1) capability of the high-elevation radar to detect summer convective heavy rain events at the regional scale, (2) added value of the low-elevation radar for regular and heavy rainfall estimation in the Grenoble city, (3) radar capability for estimating winter snow accumulation at high altitudes. Such assessments will rely on existing raingauge networks and the Météo France snow research station at Col de Porte (1160 m).

The MR2 topic will be precisely defined with the candidate to account for his/her interests and skills. A joint PhD funding by MEDD and Labex osug@2020 will be searched in 2017 for the continuation of the M2R work.