Recent studies of Arctic Amplification (AA) suggest that the Arctic has been warming about four times faster compared to the global average. Results from some models participating in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) suggest an emergent constraint linking oceanic heat convergence to declining sea ice cover in the Arctic Ocean.  Impacts of AA on mid-latitude weather and climate remain disputable, in part due to insufficient data and model limitations. While the CMIP6 multi-model ensemble mean sea ice extent and area compare well against the available historical observations, significant biases in individual model simulated sea ice states persist, resulting in the continued large CMIP model spread. The limited skill in model historical simulations of the Arctic climate system affects the reliability of their future projections.

In this presentation we will discuss the latest results from two Earth system models (ESMs), the Regional Arctic System Model (RASM) and the Energy Exascale Earth System Model with grid refinements in the pan-Arctic region (E3SM-Arctic). Dynamical downscaling using high-resolution RASM configurations allows focused process-level studies of the past, present, and future Arctic climate system, while E3SM-Arctic is aimed to improve the physical representation of the Arctic consistent within the global Earth system. Both models have been designed and used to address some of the outstanding knowledge gaps and persistent CMIP model biases as well as the national requirements for advanced modeling and prediction capability in the Arctic. We will report on the progress in addressing some of these objectives, including on the importance of oceanic forcing of sea ice and regional feedbacks related to air-sea interactions along the warm water pathways into the central Arctic, as part of the High-Latitude Application and Testing of Earth System Models (HiLAT-RASM) project.