Goelzer Heiko, Nowicki Sophie, Edwards Tamsin, Beckley Matthew, Abe-Ouchi Ayako, Aschwanden Andy, Calov Reinhard, Gagliardini Olivier, Gillet-Chaulet Fabien, Golledge Nicholas R, Gregory Jonathan, Greve Ralf, Humbert Angelika, Huybrechts Philippe, Kennedy Joseph H, Larour Eric, Lipscomb William H, Clećh Sébastien Le, Lee Victoria, Morlighem Mathieu, Pattyn Frank, Payne Antony J, Rodehacke Christian, Rückamp Martin, Saito Fuyuki, Schlegel Nicole, Seroussi Helene, Shepherd Andrew, Sun Sainan, van de Wal Roderik, Ziemen Florian A
Utrecht University, Institute for Marine and Atmospheric Research (IMAU), Utrecht, Netherlands.
Laboratoire de Glaciologie, Université Libre de Bruxelles, Brussels, Belgium.
Cryosphere. 2019 Apr;12(4):1433-1460. doi: 10.5194/tc-12-1433-2018. Epub 2019 Apr 19.
Earlier large-scale Greenland ice sheet sea-level projections (e.g., those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. The goal of the initMIP-Greenland intercomparison exercise is to compare, evaluate and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within the Coupled Model Intercomparison Project - phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of 1) the initial present-day state of the ice sheet and 2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly), and should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap, but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.
早期对格陵兰冰盖的大规模海平面预测（例如在“冰2海”和“海平面上升研究倡议”期间进行的预测）表明，冰盖的初始条件对预测有很大影响，并带来了重要的不确定性。“初始化MIP-格陵兰”对比实验的目标是比较、评估和改进冰盖建模界所使用的初始化技术，并估计模拟质量变化中的相关不确定性。“初始化MIP-格陵兰”是“ISMIP6”（CMIP6的冰盖模型对比项目）中一系列冰盖模型对比活动中的首个项目，而“ISMIP6”是耦合模式比较计划第六阶段（CMIP6）中专注于冰盖的主要活动。针对格陵兰大尺度冰盖设计了两个实验，以便参与模型之间能够就以下两方面进行对比：1）冰盖当前的初始状态；2）在两个理想化的向前实验中的响应。向前实验用于根据模型漂移（无额外强迫的向前运行）和对大扰动（规定的表面质量平衡异常）的响应来评估初始化，不应将其解释为海平面预测。我们展示并讨论了一些结果，这些结果突出了该领域用于生成格陵兰冰盖初始状态的数据集、边界条件和初始化技术的多样性。我们发现在模拟冰盖重叠区域，各模型对表面质量平衡变化的动态响应总体上具有良好的一致性，但因冰盖初始大小不同而存在差异。对于参与过早期对比实验的模型，控制实验中的模型漂移有所减少。
