Analysis and Comparison of Greenland Ice Sheet Surface Mass Balance and Energy Budget in E3SM
The Greenland Ice Sheet (GrIS) is the largest cryospheric contributor to sea level rise, and its contribution is expected to increase as polar temperatures continue to rise. Over half of the total ice loss from the GrIS has been attributed to surface melt of snow and ice. Thus, it is increasingly important to accurately simulate the GrIS surface mass balance (SMB) and surface energy budget (SEB). Over the past few years, the physical parameterizations of snow and ice physical processes have been improved in the Department of Energy Earth system model (E3SM) relative to the Community Earth System Model (CESM). These modifications include the snow densification scheme and the representation of bare ice albedo. There have been various intermodel comparisons of GrIS SMB, which have been validated against in situ and remote sensing observations. Previous comparisons have shown that the reanalysis-driven Regional Atmospheric Climate model (RACMO) simulates more accurate SMB than CESM. This is a result of RACMO being specifically developed to capture high resolution spatial variability, snow and ice processes, and precipitation patterns over the GrIS. However, the GrIS SMB and SEB simulated by E3SM has never been comprehensively evaluated against observational data or compared to regional models. This work will compare ERA5-driven simulations of SMB and SEB from E3SM and RACMOv2.4 to a suite of observational data, which will provide insight into how accurately E3SM simulates historical SMB and SEB and will highlight physical processes that need to be improved in E3SM.