E3SMv0‐HiLAT: A Modified Climate System Model Targeted for the Study of High‐Latitude Processes

Abstract

We document the configuration, tuning, and evaluation of a modified version of the Community Earth System Model version 1 (Hurrell et al., 2013, https://doi.org/10.1175/BAMS-D-12), introduced here as E3SMv0‐HiLAT, intended for study of high‐latitude processes. E3SMv0‐HiLAT incorporates changes to the atmospheric model affecting aerosol transport to high northern latitudes and to reduce shortwave cloud bias over the Southern Ocean. An updated sea ice model includes biogeochemistry that is coupled to an extended version of the ocean model's biogechemistry. This enables cloud nucleation to depend on the changing marine emissions of aerosol precursors, which may be expected in scenarios with strongly changing sea ice extent, oceanic stratification and associated nutrient availability, and atmospheric state. An evaluation of the basic preindustrial state of E3SMv0‐HiLAT is presented in order to ensure that its climate is adequate to support future experimentation. Additional capability is not achieved without some cost, relative to the extraordinarily well‐tuned model from which it was derived. In particular, a reduction of bias in cloud forcing achieved over the Southern Hemisphere also allows for greater Southern Ocean sea ice extent, a tendency that has been partially but not fully alleviated through experimentation and tuning. The most interesting change in the behavior of the model may be its response to greenhouse gas forcing: While the climate sensitivity is found to be essentially unchanged from that of Community Earth System Model version 1, the adjusted radiative forcing has increased from within one standard deviation above that of Coupled Model Intercomparison Project Phase 5 models to nearly two standard deviations.

Labrador Sea freshening linked to Beaufort Gyre freshwater release

“…The model used in this study is an eddy-permitting, global ocean-sea ice configuration 26 of the E3SMv0-HiLAT (Energy Exascale Earth System Model version 0 configured for High-Latitude Application and Testing) model 58 developed at Los Alamos National Laboratory. This model configuration, which we refer to as HiLAT03, has been documented in Zhang et al 26 .…”

Emergent Relationships Among Sea Ice, Longwave Radiation, and the Beaufort High Circulation Exposed Through Parameter Uncertainty Analysis

“…E3SMv0‐HiLAT (EHV0) is a fully coupled climate system developed for the simulation of high‐latitude processes. Extensive description and performance assessment of the model have been documented in Hecht et al (). EHV0 evolves from the Community Earth System Model (Hurrell et al, ) and uses the Version 5 of the Community Atmosphere Model with the spectral element dynamical core (CAM5‐SE; Dennis et al, ).…”

FEOTS: A New Offline Code for the Fast Equilibration of Tracers in the Ocean

“…FEOTS is used for offline tracer simulations using transport operators diagnosed from a comprehensive ocean model, the "parent model". Here we apply FEOTS to the Parallel Ocean Program, in the framework of the E3SMv0-HiLAT climate model (Hecht et al, 2019). Our specific configuration is described in Zhang et al (2019).…”