Earth system/ice-sheet coupling is an area of recent, major Earth System Model (ESM) development. This work occurs at the intersection of glaciology and climate science and is motivated by a need for robust projections of sea-level rise. The Community Ice Sheet Model version 2 (CISM2) is the newest component model of the Community Earth System Model version 2 (CESM2). This study describes the coupling and novel capabilities of the model, including: (1) an advanced energy-balance-based surface mass balance calculation in the land component with downscaling via elevation classes; (2) a closed freshwater budget from ice sheet to the ocean from surface runoff, basal melting, and ice discharge; (3) dynamic land surface types; and (4) dynamic atmospheric topography. The Earth system/ice-sheet coupling is demonstrated in a simulation with an evolving Greenland Ice Sheet (GrIS) under an idealized high CO₂ scenario. The model simulates a large expansion of ablation areas (where surface ablation exceeds snow accumulation) and a large increase in surface runoff. This results in an elevated freshwater flux to the ocean, as well as thinning of the ice sheet and area retreat. These GrIS changes result in reduced Greenland surface albedo, changes in the sign and magnitude of sensible and latent heat fluxes, and modified surface roughness and overall ice sheet topography. Representation of these couplings between climate and ice sheets is key for the simulation of ice and climate interactions.

中文翻译：

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耦合社区地球系统模型 v2 – 社区冰盖模型 v2 (CESM2-CISM2) 的描述和演示


地球系统/冰盖耦合是最近地球系统模型（ESM）发展的一个主要领域。这项工作发生在冰川学和气候科学的交叉领域，其动机是对海平面上升进行强有力的预测。社区冰盖模型版本 2 (CISM2) 是社区地球系统模型版本 2 (CESM2) 的最新组件模型。本研究描述了该模型的耦合和新颖功能，包括：（1）在陆地部分中基于先进的能量平衡的表面质量平衡计算，并通过高程等级进行降尺度； （2）从冰盖到海洋的地表径流、基底融化和冰排放的封闭淡水预算； (3)动态地表类型； (4)动态大气地形。在理想化的高 CO ₂情景下，通过不断变化的格陵兰冰盖 (GrIS) 进行模拟，演示了地球系统/冰盖耦合。该模型模拟了烧蚀区域的大幅扩张（地表烧蚀超过积雪）和地表径流的大幅增加。这导致流入海洋的淡水通量增加，以及冰盖变薄和区域退缩。这些 GrIS 变化导致格陵兰岛表面反照率降低、感热和潜热通量的符号和大小发生变化，以及表面粗糙度和整体冰盖地形的改变。气候和冰盖之间的这些耦合的表示是模拟冰和气候相互作用的关键。