Equipe ASTER (Assemblage du Système Terre et Etude des Rétroactions climatiques)

  Main activities

Development and validation of CNRM-CM global coupled climate model

  • CNRM-CM3.1 was released in March 2004. This model was used by Météo-France to produce historical and future climate simulations that were included in CMIP3 database (Coupled Model Intercomparison Project phase 3). The IPCC fourth assessment report (IPCC-AR4) was based on this dataset. A list of publications mentioning CNRM-CM3 can be found here.
  • CNRM-CM5 was developed in collaboration with Cerfacs and released in May 2010. It is based on the coupled core ARPEGE5 - NEMO3.2. It has a current resolution of about 1° on the horizontal and has 31 vertical levels in the atmosphere and 42 in the ocean. Like its predecessor, this model will contribute to CMIP and the upcoming IPCC report (September 2013).
  • New components of the climate system are being introduced in CNRM-CM, like ocean biogeochemistry, land carbon cycle and interactive atmospheric chemistry, in collaboration with IPSL (Paris). We also plan to implement an improved snow scheme (ISBA-ES) in CNRM-CM, interactive ice sheets (GRISLI model, LGGE, Grenoble, France). On the longer term, a dynamic vegetation model will be also implemented in our earth system.

 Study of past and future climate changes

Simulations of different past climates have been performed with CNRM-CM, like the last interglacial age (131-115 ky BP) and the last glacial maximum (21 ky BP), and the last millennium (with a particular focus on 1860-present). CNRM-CM has also been widely used to simulate future climates (up to 2100). A few stabilisation simulations of the 2100-2300 climate have also been run. Most of these simulations are run in the framework of national or international projects (European projects, WCRP). Some of them dynamically downscaled. These simulations allow to study long term climate feedbacks, in particular feedbacks involving interactions between the ocean, atmosphere, cryosphere and land-use changes.

 Team projects

  • FP6-ENSEMBLES : the aim of this project (ended in Dec. 2009) was to run an ensemble prediction system based on the principal state-of-the-art, high resolution, global and regional Earth System models developed in Europe, validated against quality controlled, high resolution gridded datasets for Europe, to produce an objective probabilistic estimate of uncertainty in future climate at the seasonal to decadal and longer timescales. ASTER has studied thermohaline circulation – sea ice – atmosphere feedbacks in CMIP3 simulations run with CNRM-CM3.
  • FP7-COMBINE (full description of the project and its different workpages on the web-site) : For ASTER, participating to this project implies, as a first step, to complete the CMIP5 simulations (decadal and centennial) with CNRM-CM5. Then, different aspects of CNRM-CM5 coupled climate system have to be improved. In particular, the impact of land-use changes on the carbon cycle will be studied, the modelling of snow, sea ice will be improved and ice-sheets will be implemented in CNRM-CM5 and the initialisation of sea ice will be improved. Finally, new climate simulations will be run with CNRM-CM5, in order to quantify the changes in climate sensitivity and individual climate feedbacks due to the inclusion of new important climate processes.
  • LEFE-CHARMANT (French national project, description here, in French) : Assess the impact of climate change on the mass balance of the Antarctic ice sheet during the 21st century
  • ANR-NEEM-France (French national project) : Impact of climate change on the Greenland ice sheet (coupled simulations of the last interglacial, present-day and future climates with CNRM-CM3)
  • ANR-CECILE (French national project) : Coastal Environmental Changes : Impact of sea LEvel rise
  • LEFE-QUASPPER (French national project) : Observation and modelling of snow