Print Email Facebook Twitter Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss Title Global Warming Threshold and Mechanisms for Accelerated Greenland Ice Sheet Surface Mass Loss Author Sellevold, R. (TU Delft Physical and Space Geodesy) Vizcaino, M. (TU Delft Physical and Space Geodesy) Date 2020 Abstract The Community Earth System Model version 2.1 (CESM2.1) is used to investigate the evolution of the Greenland ice sheet (GrIS) surface mass balance (SMB) under an idealized CO2 forcing scenario of 1% increase until stabilization at 4× pre-industrial at model year 140. In this simulation, the SMB calculation is coupled with the atmospheric model, using a physically based surface energy balance scheme for melt, explicit calculation of snow albedo, and a realistic treatment of polar snow and firn compaction. By the end of the simulation (years 131–150), the SMB decreases with 994 Gt yr−1 with respect to the pre-industrial SMB, which represents a sea-level rise contribution of 2.8 mm yr−1. For a threshold of 2.7-K global temperature increase with respect to pre-industrial, the rate of expansion of the ablation area increases, the mass loss accelerates due to loss of refreezing capacity and accelerated melt, and the SMB becomes negative 6 years later. Before acceleration, longwave radiation is the most important contributor to increasing energy for melt. After acceleration, the large expansion of the ablation area strongly reduces surface albedo. This and much increased turbulent heat fluxes as the GrIS-integrated summer surface temperature approaches melt point become the major sources of energy for melt. To reference this document use: http://resolver.tudelft.nl/uuid:31837bcd-e702-4a60-9cd2-df5b7e429147 DOI https://doi.org/10.1029/2019MS002029 ISSN 1942-2466 Source Journal of Advances in Modeling Earth Systems, 12 (9), 1-18 Part of collection Institutional Repository Document type journal article Rights © 2020 R. Sellevold, M. Vizcaino Files PDF 2019MS002029.pdf 24.39 MB Close viewer /islandora/object/uuid:31837bcd-e702-4a60-9cd2-df5b7e429147/datastream/OBJ/view