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

该项目的重点是东南极洲的托滕和德曼冰川，它们受到冰架融化的影响。然而，限制导致融化的海洋热含量的现场观测是有限的。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仪(阿拉莫剖面仪)遥测冰架前缘附近重复的水文剖面，以补充这些地区其他计划的船基工作。遥感数据将用于更新和改进对每个大陆架的熔化速度的估计。结合的熔融和海洋数据将被用来约束针对海洋温度的空穴融化的参数化传递函数，改进目前基于有限数据的参数化。这些融化函数将与气候模型中的海洋温度一起使用，以迫使盆地规模的开源冰流模型确定各种情况下的百年尺度响应，有助于减少南极洲这一地区海平面贡献的不确定性。可能进一步改变反应的熔化以外的其他过程也将被检查。例如，随着水流速度的增加，对冰架剪切边缘的破坏也会增加，这可能会带来积极的反馈。另一个潜在因素是冰架面积的减少，这会减少支撑并增加冰的损失。为了研究这些过程，利用不同程度的破坏和冰架损失进行的数值实验将有助于确定这些因素可能进一步提高海平面的程度。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快速变化的极地陆架海进行现场监测的技术准备情况，为从目前了解较少的偏远地区对海洋水文性质的观测进行变革性的扩展铺平道路。

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.