Climate Change and Hydrological Extreme Evolution Through a Multifractal Analysis of a Mesocale Model

Auguste Gires (1) , D Schertzer (1) , Ioulia Tchiguirinskaia (1) , J.-F. Royer , J.-L. Dufresne , J. Desplat , S. Lovejoy

1 CEREVE - Centre d'Enseignement et de Recherche Eau Ville Environnement

In its last report, the IPCC (http://www.ipcc.ch) emphasizes the question of scales and the necessity to obtain much finer resolutions for hydrological processes in climate scenarios to assess the time evolution of the hydrological extremes. One may bridge up the gap between meteorological and hydrological scales with the help of downscaling techniques, which are statically or/and physically based. In particular, one may exploit the scaling properties of the precipitation to downscale it either numerically by stochastic subgrid modeling or theoretically with the help of a few scaling exponents (Royer et al. C.R. Geoscience, 340, 2008). However, we first suggest that these techniques need to be validated not only with the help of empirical data of the actual climatology, but also by comparison with mesoscale numerical simulations in normal and pertubated conditions. Secondly, we present how to proceed to such a comparison with the help of a multifractal analysis of the hydrometeorological fields of the Meso-NH model (Meteo-France/CNRM and Laboratoire d'Aérologie, Toulouse, France), a model which has been rather extensively used for mesoscale research and should shortly become operational.

Domaines: Sciences de l'environnement

Auguste Gires, D Schertzer, Ioulia Tchiguirinskaia, J.-F. Royer, J.-L. Dufresne, et al.. Climate Change and Hydrological Extreme Evolution Through a Multifractal Analysis of a Mesocale Model. American Geophysical Union Fall Meeting 2008, 2008, San Francisco, United States. pp.Ng42b-03-Ng42b-02. ⟨hal-00742386⟩