Climate sensitivity of western Antarctic Peninsula ice shelves (CSAPIS)

南极半岛西部冰架的气候敏感性（CSAPIS）

• 批准号: 502022985
• 负责人: Professor Dr. Matthias Holger Braun
• 金额: --
• 依托单位: College of Earth, Ocean, and Atmospheric Sciences
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/502022985?language=en
• 关键词: Climate; sensitivity; western; Antarctic; Peninsula

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).

在过去的几十年中，南极西部半岛西部的大多数冰架表现出来，或者在过去几十年中经历了相当大的撤退甚至完全瓦解。最近的研究将这一部分与温暖的圆形深水（CDW）的上升联系起来，这应该影响西南部南极半岛地区。但是，确切的过程和机制以及该区域对进一步的冰架和冰川变薄和撤退的敏感性尚不确定或未受到良好约束。这部分是因为缺乏观察结果和苛刻的建模工作。在这项研究中，我们建议分析遥感数据的时间序列，以得出各种冰川变量，例如表面速度，表面抬高变化，接地线和冰面位置以及结构变量。我们将为西南南极半岛的整个大型集水区提供此分析。我们将结合遥感数据集，以使用两种独立方法来计算时间上的高分辨率冰出排放估计值。这些数据集将为国际努力做出贡献，例如冰期质量平衡间比较锻炼（IMBIE）或严重性变化范围内面板（IPCC）的下一个报告。然后，上述遥感产品将用于使用ICE动态模型的冰搁置静修处的正向模拟中的校准和验证。使用的冰流模型是Blatter-Pattyn近似中的冰片和海平面系统模型（ISSM），在接地线处的设想分辨率降至200-500 m。数值建模研究的目的是两个方面。第一步，研究了最近正在进行的变化的机制。在这里，我们着重于冰架支撑的重要性以及冰架熔化的影响（冰山相互作用）。这一步骤在评估瞬态仿真质量的遥感产品上大大建立。在第二步中，估计冰架和冰川支流的未来稳定性。根据协调的区域缩减实验（极性 - 局部）建模策略，重点是代表性浓度途径（RCP）8.5方案。为了解决这些问题，我们将依靠合适的海洋和大气领域。特别是，我们努力使用有限的元素冰山模型（FESOM）使用正在进行的努力的数据集，以在模型框架中包括冰架腔（正在进行的echam6-fesom耦合，用于气候模型对比度的项目（CMIP）6和极性 - 层次活动）。