The software, titled E3SMv0-HiLAT, is a novel, modified version of the Community Earth System Model version 1 (Hurrell et al., 2013, https://doi.org/10.1175/BAMS-D-12), intended for study of high-latitude processes. E3SMv0-HiLAT incorporates changes and new features in the atmospheric model; these changes affect aerosol transport to high northern latitudes and reduce shortwave cloud bias over the Southern Ocean. Additionally, new features are introduced to the ocean biogeochemistry to improve representation of high-latitude phytoplankton groups, and two-way coupling is implemented between the biogeochemistry in the sea ice and ocean models. The modifications also include a dynamic coupling of the ocean flux of aerosol precursors into the atmosphere model, which enables these marine emissions of aerosol precursor emissions to respond to changes in sea ice extent, ocean stratification and associated nutrient availability, and atmospheric state.