# The DOE E3SM Coupled Model Version 1: Overview and Evaluation at Standard Resolution

Journal: Journal of Advances in Modeling Earth Systems
Year of Publication: 2019
Publication Date: 03/2019

This work documents the first version of the U.S. Department of Energy (DOE) new Energy Exascale Earth System Model (E3SMv1). We focus on the standard resolution of the fully-coupled physical model designed to address DOE mission-relevant water cycle questions. Its components include atmosphere and land (110km grid spacing), ocean and sea ice (60km in the mid-latitudes and 30km at the equator and poles), and river transport (55km) models. This base configuration will also serve as a foundation for additional configurations exploring higher horizontal resolution as well as augmented capabilities in the form of biogeochemistry and cryosphere configurations. The performance of E3SMv1 is evaluated by means of a standard set of Coupled Model Intercomparison Project Phase 6 Diagnosis, Evaluation, and Characterization of Klima (CMIP6 DECK) simulations consisting of a long pre-industrial control, historical simulations (ensembles of fully coupled and prescribed SSTs) as well as idealized CO$_2$ forcing simulations. The model performs well overall with biases typical of other CMIP-class models, although the simulated Atlantic Meridional Overturning Circulation is weaker than many CMIP-class models. While the E3SMv1 historical ensemble captures the bulk of the observed warming between pre-industrial (1850) and present-day, the trajectory of the warming diverges from observations in the second half of the 20th century with a period of delayed warming followed by an excessive warming trend. Using a two-layer energy balance model, we attribute this divergence to the model's strong aerosol-related effective radiative forcing (ERF$_{\mathrm{ari+aci}}$ = -1.65 W m$^{-2}$) and high equilibrium climate sensitivity (ECS = 5.3 K).

DOI: 10.1029/2018ms001603
Citation:
Golaz, J, PM Caldwell, LP Van Roekel, MR Petersen, Q Tang, JD Wolfe, G Abeshu, et al.  2019.  "The DOE E3SM Coupled Model Version 1: Overview and Evaluation at Standard Resolution."  Journal of Advances in Modeling Earth Systems.  https://doi.org/10.1029/2018ms001603.
##### Related Publication(s):
Hecht, MW, M Veneziani, W Weijer, B Kravitz, S Burrows, D Comeau, E Hunke, et al.  2019.  "E3SMv0‐HiLAT: A Modified Climate System Model Targeted for the Study of High Latitude Processes."  Journal of Advances in Modeling Earth Systems.  https://doi.org/10.1029/2018MS001524.