Modeling the Greenland ice sheet response to climate change on different timescales

由于人为的全球变暖，格陵兰冰盖可能会在未来数千年内对海平面上升造成多达7米的影响。随着气温的升高，冰盖会经历更多的表面融化，最终将不再能够维持目前的大小。人们普遍认为，如果全球地球温度将超过一定阈值，格陵兰冰盖最终将完全融化。然而，导致跨过这一门槛的全球变暖程度尚不为人所知。在长时间尺度上，冰盖对气候变化的敏感性将在很大程度上取决于地表物质平衡的变化。在这个项目中，将开发一种新的方法来模拟格陵兰冰盖的表面质量平衡，通过基于物理的表面能量和质量平衡界面将中等复杂性的区域气候模式耦合到冰盖模型。这种方法将使我们能够在不同的气候变化情景下对格陵兰冰盖进行大量长期模拟，以改进对格陵兰冰盖对气候变化的敏感性以及导致其完全融化的关键气候阈值的估计。通过这个项目，我们将有助于更好地了解格陵兰冰盖对未来海平面上升的贡献，并有助于评估地球系统发生不可逆转变化的可能性。

The Greenland ice sheet could potentially contribute up to 7 m to sea level rise in the coming millennia due to anthropogenic global warming. As temperatures increase, the ice sheet experiences more surface melt and will eventually no longer be able to sustain its current size. It is generally believed that if the global Earth’s temperature will exceed a certain threshold value, the Greenland ice sheet will eventually melt completely. However, the magnitude of global warming which will lead to crossing this threshold is not well known. The sensitivity of the ice sheet to climate change on long timescales will largely depend on surface mass balance change. In this project, a novel approach will be developed for modeling the surface mass balance of the Greenland ice sheet by using a regional climate model of intermediate complexity coupled to an ice sheet model via a physically-based surface energy and mass balance interface. Such an approach will allow us to perform a large ensemble of long-term simulations of the Greenland ice sheet under different climate change scenarios to refine estimates of the Greenland ice sheet sensitivity to climate change and the critical climate thresholds leading to its complete melting. With this project, we will contribute to a better understanding of the Greenland Ice Sheet contribution to future sea level rise and to the assessment of the probability of irreversible changes in the Earth system.