West Antarctic Ice Sheet Surface Melting: Recognition Controls and Significance

该奖项支持从物理和历史的角度，使用多种技术(雪坑、冰芯、自动气象站和遥感数据，以及熔体生成实验)，从物理和历史角度研究南极洲西部罗斯湾融化的发生。当温度上升到某个阈值以上时，极地冰盖上的表面就会融化。查看南极洲过去表面融化事件的各种记录，就会发现特别是高温发生的变化。熔体和其他古温度计(钻孔温度、同位素等)的联合解释可能会允许季节性分辨的古温度计。冰盖表面的融化可以用很多方法来测量。空间微波传感器记录了近地表发生的液态水或重新冻结的冰层。自动气象站(AWS)记录与液态水发展有关的高温。雪坑和冰芯的研究表明，在雪坑和冰芯中，足够多的液态水重新冻结，导致了明显不同的层形成。这些熔体发生的不同测量方法并不完全相同，目前还没有很好地相互校准。这一拟议的项目将能够确定不同的融化措施之间的相互关系。这些知识将帮助冰川学家了解融化和气候在过去如何变化和影响南极过程，以及它们未来可能如何变化。将特别关注关键的罗斯冰架和西南极洲的Siple Dome地区。

This award provides support to study the occurrence of melting in the Ross Embayment of West Antarctica, from a physical and historical perspective, using a combination of techniques (snow-pit, ice-core, AWS, and remotely sensed data, and experiments on melt generation). Surface melting on polar ice sheets occurs as temperatures increase above some threshold. Looking at a variety of records of past surface melting events in Antarctica will reveal changes in the occurrence of especially high temperatures. Joint interpretation of melt and other paleothermometers (borehole temperatures, isotopes, etc.) may allow seasonally resolved paleothermometry. Melting on the surface of an ice sheet can be measured in many ways. Space-based microwave sensors record the occurrence of liquid water or refrozen ice layers in the near surface. Automatic Weather Stations (AWS) record the high temperatures that are linked to development of liquid water. Snow-pit and ice-core studies show layers where refreezing of sufficient liquid water has caused a visibly distinct layer to form. These different measures of melt occurrence are not identical, and are presently not calibrated well to each other. This proposed project will enable the determination of how different measures of melting are related to each other. This knowledge will help glaciologists to learn how melting and climate have changed and affected Antarctic processes in the past, and how they may change in the future. Special focus will be on the critical Ross Ice Shelf and Siple Dome regions of West Antarctica.