Climate sensitivity of western Antarctic Peninsula ice shelves (CSAPIS)

在过去的几十年里，南极半岛西部的大多数冰架显示出或经历了相当大的退缩甚至完全解体。最近的研究将这部分与温暖的环极深水（CDW）上涌联系起来，这被认为特别影响南极半岛西南部地区。然而，确切的过程和机制以及该地区对冰架和冰川进一步变薄和退缩的敏感性尚不清楚或没有得到很好的约束。这在一定程度上是由于缺乏观测和苛刻的建模工作。在这项研究中，我们建议通过分析遥感数据的时间序列来获得各种冰川变量，如地表速度、地表高程变化、接地线和冰锋位置以及结构变量。我们将为南极半岛西南部的整个大型集水区提供这种分析。我们将结合遥感数据集，用两种独立的方法计算时间上高分辨率的冰质量流量估算。这些数据集将对诸如冰盖质量平衡相互比较活动（IMBIE）或政府间气候变化专门委员会（IPCC）的下一份报告等国际努力作出贡献。然后，上述遥感产品将用于用冰动力模式对该地区冰架退缩进行正演模拟的校准和验证。所采用的冰流模型是blater - pattyn近似的冰盖和海平面系统模型（ISSM），设想的分辨率在接地线上低至200-500米。数值模拟研究的目的是双重的。在第一步中，研究了最近正在进行的变化的机制。在这里，我们重点讨论了冰架支撑的重要性和冰架融化（冰-海相互作用）的影响。这一步骤在很大程度上依赖于评估瞬态模拟质量的遥感产品。第二步，估计冰架和冰川支流未来的稳定性。根据协调区域降尺度实验（Polar-CORDEX）建模策略，重点是代表性浓度路径（RCP） 8.5情景。为了解决这些问题，我们将依靠合适的海洋和大气场。特别是，我们努力使用正在进行的有限元海冰-海洋模型（FESOM）的数据集，在建模框架中包括冰架空洞（正在进行的ECHAM6-FESOM耦合气候模式比较项目（CMIP） 6和Polar-CORDEX活动）。

Most ice shelves on the western Antarctic Peninsula show or have experienced considerable retreat or even complete disintegration in the last few decades. Recent studies have linked this partly to upwelling of warm Circumpolar Deep Water (CDW), which is supposed to influence particularly the southwestern Antarctic Peninsula region. However, the exact processes and mechanisms as well as the sensitivity of the region to further ice shelf and glacier thinning and retreat are not known or not well constrained. This is partly because of lacking observations and the demanding modelling efforts. In this study, we propose to analyse time series of remote sensing data to derive various glaciological variables such as surface velocities, surface elevation change, grounding line and ice front positions as well as structural variables. We will provide this analysis for entire large-scale catchments on the southwestern Antarctic Peninsula. We will combine the remote sensing data sets to compute temporally high-resolution ice mass discharge estimates with two independent methods. Those data sets will form a contribution to international efforts such as Ice sheet Mass Balance Inter-comparison Exercise (IMBIE) or the next report of the Intergovernmental Panel of Climate Change (IPCC). The above-mentioned remote sensing products will then be used for calibration and validation in forward simulations for the ice shelve retreat in the region with an ice dynamic model. The employed ice flow model is the Ice-Sheet and Sea-level system model (ISSM) in Blatter-Pattyn approximation and an envisaged resolution down to 200-500 m at the grounding line. The aim of the numerical modelling studies is two-fold. In a first step, the mechanisms for recent ongoing changes are investigated. Here, we focus on the importance of ice-shelf buttressing and the impact of ice shelf melting (ice-ocean interaction). This step heavily builds on remote sensing products assessing the quality of the transient simulations. In a second step, the future stability of ice shelves and glacier tributaries is estimated. In accordance with the COordinated Regional Downscaling EXperiment (Polar-CORDEX) modelling strategy, the focus is on the Representative Concentration Pathway (RCP) 8.5 scenario. To tackle these questions, we will rely on suitable oceanic and atmospheric fields. In particular, we strive to use data-sets of the ongoing efforts with the Finite Element Sea ice-Ocean Model (FESOM) to include ice shelf cavities in the modelling framework (ongoing ECHAM6-FESOM coupling for the Climate Model Intercomparison Project (CMIP) 6 and from the Polar-CORDEX activity).