Axis 1 : Regional climate trends and variability

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The C2H activities focus on the interactions between climate, cryosphere and hydrosphere at global to regional scales. Climate change is expected to impact the mean state of the climate system, but to increase also the frequency and the intensity of extreme events. The C2H team studies the response of the ice bodies and the hydrogical cycle to the climate variability in mountainous areas for the present period and in future projections, through two parallel approaches :

(i) Climate and cryosphere feedbacks at high latitudes and in mountain regions (Andes, Himalayas, Alps) are investigated with a focus on the links between the cryosphere and the modes of climate variability, the trends induced by anthropogenic pressures and the amplification of the climate change specific to cold areas. The team contributes to model intercomparison exercises and carries out specific climate simulations using global and limited-area models. New parametrisations and original configurations are also set up to reduce model biases which are currently especially pronounced in cold regions.

(ii) The team is developing both modelling and observational approaches to understand the atmospheric drivers of snow cover and glacier variations. C2H focuses on the study of physical processes controlling moisture advection, cloud cover variability or the formation of hydrometeors. A specific focus is made on precipitation rates and solid-to-liquid ratio at high elevations, because these variables are crucial for the cryosphere. The team is particularly interested in coupling large-scale atmospheric circulation with local meteorological and hydrological processes presenting a large spatio-temporal variability due to the complex topography and to the heterogeneous surface conditions found in mountainous areas.