Earth system model ARTS-ESM-L: basic properties, simulation of present climate and historical climate changes

The paper describes a new Earth system model ARTS\nobreakdash-ESM\nobreakdash-L developed on the basis of climate model INMCM48. The results of idealized CMIP7 DECK experiments, as well as simulations of the present-day climate and historical climate changes are evaluated. In the new model, equilibrium climate sensitivity increased from 1.8 K to 2.9 K, transient climate response increased from 1.3 K to 1.8 K in comparison with INMCM48. All these values for ARTS\nobreakdash-ESM\nobreakdash-L are close to the CMIP6 model mean, while INMCM48 had the lowest ones among the CMIP6 models. The reason for the substantial increase in climate sensitivity increase is the switching on prognostic cloud parameterization.The simulation of the present-day atmosphere, ocean, sea ice and land surface climate state is discussed. The model demonstrates moderate improvements in most of considered parameters. The ARTS\nobreakdash-ESM\nobreakdash-L simulates well the time series of observed global mean near-surface air temperature, low stratospheric temperature, land snow extent change in CMIP7 historical simulations (1850--2021). Simulation of climate and carbon cycle changes using historical anthropogenic carbon emissions and land use changes shows that the model is capable to reproduce land, ocean and atmospheric carbon uptake reasonably well.The ARTS\nobreakdash-ESM\nobreakdash-L model is now available for usage in the CMIP7 Assessment Fast Track experiments and paleoclimate simulations.