Evaluation of CNRM Earth System Model, CNRM-ESM2-1: Role of Earth System Processes in Present-Day and Future Climate
|Author(s)||Seferian Roland1, Nabat Pierre1, Michou Martine1, Saint-Martin David1, Voldoire Aurore1, Colin Jeanne1, Decharme Bertrand1, Delire Christine1, Berthet Sarah1, Chevallier Matthieu1, Senesi Stephane1, Franchisteguy Laurent1, Vial Jessica2, Mallet Marc1, Joetzjer Emilie1, Geoffroy Olivier1, Gueremy Jean-Francois1, Moine Marie-Pierre3, Msadek Rym3, Ribes Aurelien1, Rocher Matthias1, Roehrig Romain1, Salas-Y-Melia David1, Sanchez Emilia3, Terray Laurent3, Valcke Sophie3, Waldman Robin1, Aumont Olivier, Bopp Laurent2, Deshayes Julie4, Ethe Christian5, Madec Gurvan4, 6|
|Affiliation(s)||1 : Univ Toulouse, CNRS, CNRM, Meteo France, Toulouse, France.
2 : Sorbonne Univ, PSL Res Univ, Ecole Polytech, Ecole Normale Super, Paris, France.
3 : Univ Toulouse, CNRS, CERFACS, CECI, Toulouse, France.
4 : Sorbonne Univ, CNRS, IRD, LOCEAN,IPSL,MNHN, Paris, France.
5 : Inst Pierre Simon Laplace, Paris, France.
6 : Univ Grenoble Alpes, INRIA, Grenoble, France.
|Source||Journal Of Advances In Modeling Earth Systems (1942-2466) (Amer Geophysical Union), 2019-12 , Vol. 11 , N. 12 , P. 4182-4227|
|WOS© Times Cited||196|
|Note||This article also appears in: The CNRM Climate and Earth System Models for CMIP6|
This study introduces CNRM-ESM2-1, the Earth system (ES) model of second generation developed by CNRM-CERFACS for the sixth phase of the Coupled Model Intercomparison Project (CMIP6). CNRM-ESM2-1 offers a higher model complexity than the Atmosphere-Ocean General Circulation Model CNRM-CM6-1 by adding interactive ES components such as carbon cycle, aerosols, and atmospheric chemistry. As both models share the same code, physical parameterizations, and grid resolution, they offer a fully traceable framework to investigate how far the represented ES processes impact the model performance over present-day, response to external forcing and future climate projections. Using a large variety of CMIP6 experiments, we show that represented ES processes impact more prominently the model response to external forcing than the model performance over present-day. Both models display comparable performance at replicating modern observations although the mean climate of CNRM-ESM2-1 is slightly warmer than that of CNRM-CM6-1. This difference arises from land cover-aerosol interactions where the use of different soil vegetation distributions between both models impacts the rate of dust emissions. This interaction results in a smaller aerosol burden in CNRM-ESM2-1 than in CNRM-CM6-1, leading to a different surface radiative budget and climate. Greater differences are found when comparing the model response to external forcing and future climate projections. Represented ES processes damp future warming by up to 10% in CNRM-ESM2-1 with respect to CNRM-CM6-1. The representation of land vegetation and the CO2-water-stomatal feedback between both models explain about 60% of this difference. The remainder is driven by other ES feedbacks such as the natural aerosol feedback.