The new IPSL climate system model: IPSL-CM4

The estimate of future climate change and of its impact on the environment requires to increase our knowledge of the complex interactions between the atmosphere, the ocean, sea-ice, land surfaces and glaciers. These components are coupled through the cycles of energy and water, but also through biogeochemical cycles such as the carbon or the ozone cycles. One of the goals of the IPSL modeling community is to study how these different couplings can modulate climate and climate variability, and to determine how feedbacks in the Earth system control the response of climate to a perturbation such as the anthropogenic emissions of greenhouse gases. For this purpose, the Earth system model of the IPSL is developed as a modular suite of model components of the Earth system that can be use either as stand alone models or coupled to each other. This note presents the new features and results of the last version of the global IPSL coupled model that will be used to run the set of simulations planned for the next IPCC assessment. In particular, chapter 2 presents the model components of the coupled system, highlighting important features for the coupling or the quality of model simulations. Chapter 3 synthesise all the coupling procedures and the coupling environment, and chapter 4 discussed the major characteristics of the model climatology.