The DOE E3SM Coupled Model Version 1: Description and Results at High Resolution

TitleThe DOE E3SM Coupled Model Version 1: Description and Results at High Resolution
Publication TypeJournal Article
Year of Publication2019
JournalJournal of Advances in the Modeling of Earth Systems
Abstract / Summary

This study provides an overview of the coupled high-resolution version 1 of the Energy Exascale Earth System Model (E3SMv1) and documents the characteristics of a 50 year long high-resolution control simulation with time-invariant 1950 forcings following the HighResMIP protocol. In terms of global root-mean-squared error metrics, this high-resolution simulation is generally superior to results from the low-resolution configuration of E3SMv1 (due to resolution, tuning changes, and possibly initialization procedure) and compares favorably to models in the CMIP5 ensemble. Ocean and sea ice simulation is particularly improved, due to better resolution of bathymetry, the ability to capture more variability and extremes in winds and currents, and the ability to resolve mesoscale ocean eddies. The largest improvement in this regard is an ice-free Labrador Sea, which is a major problem at low resolution. Interestingly, several features found to improve with resolution in previous studies are insensitive to resolution or even degrade in E3SMv1. Most notable in this regard are warm bias and associated stratocumulus deficiency in eastern subtropical oceans and lack of improvement in El Nino. Another major finding of this study is that resolution increase had negligible impact on climate sensitivity (measured by net feedback determined through uniform +4K prescribed sea surface temperature increase) and aerosol sensitivity. Cloud response to resolution increase consisted of very minor decrease at all levels. Large-scale patterns of precipitation bias were also relatively unaffected by grid spacing.

URLhttps://doi.org/10.1029/2019MS001870
DOI10.1029/2019MS001870
Journal: Journal of Advances in the Modeling of Earth Systems
Year of Publication: 2019
Publication Date: 11/2019

This study provides an overview of the coupled high-resolution version 1 of the Energy Exascale Earth System Model (E3SMv1) and documents the characteristics of a 50 year long high-resolution control simulation with time-invariant 1950 forcings following the HighResMIP protocol. In terms of global root-mean-squared error metrics, this high-resolution simulation is generally superior to results from the low-resolution configuration of E3SMv1 (due to resolution, tuning changes, and possibly initialization procedure) and compares favorably to models in the CMIP5 ensemble. Ocean and sea ice simulation is particularly improved, due to better resolution of bathymetry, the ability to capture more variability and extremes in winds and currents, and the ability to resolve mesoscale ocean eddies. The largest improvement in this regard is an ice-free Labrador Sea, which is a major problem at low resolution. Interestingly, several features found to improve with resolution in previous studies are insensitive to resolution or even degrade in E3SMv1. Most notable in this regard are warm bias and associated stratocumulus deficiency in eastern subtropical oceans and lack of improvement in El Nino. Another major finding of this study is that resolution increase had negligible impact on climate sensitivity (measured by net feedback determined through uniform +4K prescribed sea surface temperature increase) and aerosol sensitivity. Cloud response to resolution increase consisted of very minor decrease at all levels. Large-scale patterns of precipitation bias were also relatively unaffected by grid spacing.

DOI: 10.1029/2019MS001870
Citation:
Caldwell, PM, A Mametjanov, Q Tang, L Van Roekel, J Golaz, W Lin, D Bader, et al.  2019.  "The DOE E3SM Coupled Model Version 1: Description and Results at High Resolution."  Journal of Advances in the Modeling of Earth Systems.  https://doi.org/10.1029/2019MS001870.