NSFGEO-NERC: Understanding the Response to Ocean Melting for Two of East Antarctica's Most Vulnerable Glaciers: Totten, and Denman

该项目的重点是南极洲东部受冰架融化影响的Totten和登曼冰川。然而，现场观测限制了导致融化的海洋热含量。为了填补这一空白，该项目将使用空中发射的自主微型观测器（ALAMO剖面仪）遥测回冰架前沿附近的重复水文剖面，以补充这些地区计划中的其他船基工作。遥感数据将用于提供每个大陆架融化速度的最新和改进的估计数。融化和海洋学综合数据将被用来约束参数化的传递函数，以适应海洋温度，改善目前基于有限数据的参数化。这些融化函数将与来自气候模型的海洋温度一起使用，以迫使流域规模的开源冰流模型确定各种情景的世纪规模响应，帮助减少南极洲这一部分海平面贡献的不确定性。除熔化外，可能进一步改变响应的过程也将被检查。例如，随着流速的增加，对冰架剪切边缘的损害增加，可能会引入正反馈。另一个潜在的因素是冰架范围的缩小，这会减少支撑作用，增加冰损失。为了研究这些过程，使用不同程度的损害和冰架损失的数值实验将有助于确定这些因素可能进一步增加海平面的程度。通过在极地环境中从声纳浮标发射管空中部署浮标剖面仪，该项目的长期影响将是提高对迅速变化的极地陆架海进行实地业务监测的技术准备程度，为从目前知之甚少的偏远地区彻底扩大海洋水文特性观测铺平道路。

This project focuses on Totten and Denman glaciers, East Antarctica, which are influenced by ice-shelf melting. In situ observations constraining the ocean heat content causing the melt, however, are limited. To fill this gap, the project will use Air-Launched Autonomous Micro Observer (ALAMO profilers) to telemeter back repeated hydrographic profiles near the ice-shelf fronts to complement other planned ship-based efforts in these areas. Remote sensing data will be used to provide updated and improved estimates of the melt rate for each shelf. The combined melt and oceanographic data will be used to constrain parameterized transfer functions for cavity melting in response to ocean temperature, improving on current parametrizations based on limited data. These melt functions will be used with ocean temperatures from climate models to force a basin-scale, open-source ice-flow model to determine the century-scale response for a variety of scenarios, helping to reduce uncertainty in sea level contributions from this part of Antarctica. Processes other than melt that might further alter the response will also be examined. For example, as flow speed increases, damage to ice-shelf shear margins increases, potentially introducing a positive feedback. Another potential factor is reductions in ice-shelf extent that decrease buttressing and increase ice loss. To investigate these processes, numerical experiments using varying degrees of damage and ice-shelf loss will help determine the extent to which these factors might further increase sea level. Through the air-deployment of float profilers from a sonobuoy launch tube in polar settings, a long-term impact of the project will be to raise the technology readiness of operational in-situ monitoring of the rapidly changing polar shelf seas, paving the way for a transformative expansion of observations of ocean hydrographic properties from remote areas that currently are understood poorly.