Monitoring Snow in a changing climate (MONISNOW)
ANR Edition 2011 Jeunes Chercheurs SIMI 5-6


Context: The snow cover and the atmosphere interact strongly through the energy and matter transfers across their interface. The main interaction and the most well-known, results from the strong difference in albedo between snow and other surface types. For this reason, the extent of the snow-covered areas on Earth is systematically monitored, and the presence of snow is explicitly accounted for in numerical models for weather and climate forecasts. However, the internal properties of the snow cover such as the grain size, albedo, density and thermal conductivity are generally overlooked. Yet, these properties vary significantly over time, influenced by atmospheric conditions and, in return, they have a strong impact on the atmosphere, notably through the radiative budget. Many process chains thus form snow-climate feedback loops. Although, the principle of these interactions is known, their quantification is poor due to the lack of long-term observations on the internal properties of the snowpack.

Objective: The goal of this project is to fill this deficit by 1) developing a new generation of instruments (MONISNOW) capable of observing the physical properties of the snow and of monitoring their evolution in the changing climate of the XXIst century, then by 2) exploiting these new observations to improve the formulations of snow metamorphism and of energy and matter fluxes across the surface. The ultimate goal is to integrate these improvements into general circulation models, which will provide a far better quantification of certain snow-climate feedback loops.

Step 1: The new-generation MONISNOW instruments will be capable of continuously measuring the grain size, surface roughness, spectral albedo, solar energy penetration depth, as well as temperature and thermal conductivity profiles. Together, these measurements form a coherent dataset to characterize the variables driving the energy fluxes and snow metamorphism. The instruments will be deployed in the Antarctic, the Alps and in Canada to cover a wide range of climate conditions.

Step 2: The MONISNOW data will be invaluable input for improving the Crocus modeling of metamorphism as well as energy and matter fluxes. The Crocus model was developed 20 years ago by the Centre d’Etude de la Neige (snow research center), and its metamorphism scheme is currently undergoing a major overhaul. With this data, the scheme will be tested with unprecedented accuracy because it will provide 1) a comprehensive variable set, and 2) the continuous evolution of these variables over time. Improvements of Crocus will follow and be directly available in the surface schemes of Météo-France since Crocus is part of SURFEX.

Participants: Ghislain Picard (leader)1, Laurent Arnaud1, Samuel Morin2, Marie Dumont2, Quentin Libois (PhD)1
1 Laboratoire de Glaciologie et Géophysique de l'Environnement (UMR 5183 CNRS-UJF)
54 rue Molière - Domaine Universitaire - BP 96
38402 St Martin d'Hères Cedex, FRANCE

2 Météo-France/CNRS, CNRM-GAME
Centre d'Etudes de la Neige / Snow Research Center
1441 rue de la piscine
38400 St Martin d'Hères, France

Budget: 263000€ for 4 years.