The Mountain Glacier forecast framework

全球普遍的冰川退缩已经成为全球变暖影响的标志，我们预计这种消亡将继续下去，并显著加剧全球海平面上升。冰的损失也会引起区域水资源的变化，使一些地方面临全年淡水供应的高风险。因此，在沿海影响、水资源管理和水文冰川学风险方面，更好地预测冰川退缩至关重要。该项目的总体目标是提供一个框架，以改善过去和未来的冰川体积预测。基于过程的框架将基于开源冰流模型Elmer/Ice，并将减少三个潜在的重要不确定性来源。预计来自卫星遥感的信息将不断增长，我们将改进和开发强大的数据同化方法，以推断冰下的基底地形，并校准冰流参数，以便更好地表示初始状态和冰动力学。流动模型将与一个增强的表面质量平衡模型耦合，该模型在相关的几十年时间尺度上显示出稳定的熔体关系。基于集合模拟，该框架将允许更好地量化这些不确定性的相互作用和传播。作为概念的证明，该框架将应用于法国阿尔卑斯山和科迪勒拉达尔文（智利）的冰川演变的后测和预测。之所以选择这些地点，是因为这两个冰川地点的冰流都被认为是重要的，而且还因为可以获得原位和遥感观测。这两个站点将进一步作为具有挑战性的测试设置，以仔细检查模型框架在不同气候条件和动态设置下的适用性、性能和鲁棒性。

General glacier retreat around the globe has become iconic to illustrate the effects of global warming and we anticipate that this demise will continue and significantly add to global sea-level rise. Ice loss can also induce shifts in regional water resources, putting some places at high risk of year-around freshwater availability. Better projections of glacier retreat are therefore essential in terms of coastal impact, water management and hydro-glaciological risks.The overall aim of the project is to provide a framework to improve past and future glacier volume projections. The process-based framework will be based on the open-source ice-flow model Elmer/Ice and will allow to reduce three potentially important sources of uncertainty. Anticipating the continuously growing body of information from satellite remote sensing, we will improve and develop robust data assimilation methods to infer the basal topography beneath the ice and calibrate ice-flow parameters for a better representation of the initial state and ice dynamics. The flow model will be coupled to an enhanced surface mass balance model that exhibits a stable melt relation over relevant multi-decadal timescales. Based on ensemble simulations, the framework will allow to better quantify the interaction and propagation of these uncertainties.As a proof of concept, the framework will be applied to hindcast and forecast glacier evolutions in the French Alps and in Cordillera Darwin (Chile). These sites have been chosen because for both glacier sites ice-flow is considered important and because of the availability of in-situ and remotely sensed observations. The two sites will further serve as challenging test setups to scrutinise the applicability, performance and robustness of the modelling framework under different climatic conditions and dynamic settings.