23) Impact of Arctic Mesh Refinement on Global Sea Ice State in E3SM
In collaboration with E3SM, InteRFACE has helped develop a regionally-refined coupled configuration of E3SM relevant to Arctic coastal simulation. This includes 14km marine regional refinement over the entire Arctic Ocean and North American coastal regions, coupled to a 25km atmospheric refinement extending to abyssal areas off North American coasts set upon the standard global resolution of E3SM with 30-60km and 100km ocean and atmosphere meshes, respectively. We evaluate the model during the latter part of the industrial era for E3SM version 2, comparing with observations from 1980 onward, as well as intercomparing model configuration differences over a 500-year pre-industrial control, so as to understand the impact of regional refinement in Arctic sea ice. Several clear results emerge: 1) There is a marked increase in northern hemisphere sea ice volume with regional refinement, but little improvement in Arctic sea ice extent or coastal conditions. 2) There is little improvement in E3SM as compared to the observed winter ice edge even with Atlantic regional refinement, and that the NARRM model configuration does not resolve a chronic ice-edge bias in the model. 3) Both models produce markedly different circulation patterns in the Arctic relative to the Pathfinder drift dataset, and, for certain months, when compared to each other.