Noble Gases and Helium Isotopes During Ocean2ice: Processes and Variability of Ocean Heat Transport Toward Ice Shelves in the Amundsen Sea

Ocean2ice期间的稀有气体和氦同位素：阿蒙森海冰架的海洋热传输过程和变化

• 批准号: 1341630
• 负责人: Brice Loose
• 金额: $ 38.53万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1341630&HistoricalAwards=false
• 关键词: Noble; Gases; Helium; Isotopes; During

Ice shelf mass balance is controlled by net surface accretion (precipitation minus ablation and surface melt terms), calving and basal melt along the underside of the ice shelf cavity, which is in contact with a warming ocean. Estimating the rate of basal melt is the most challenging term in this balance because it is difficult to directly observe, but is also sensitive to changes in ocean temperature and other ocean-atmospheric processes such as the sea ice cycle.This project will join the Ocean2ice program, a UK led effort to integrate state of the art instrumentation, chemical analysis and modeling with the goal of improving the dynamical representation of ice shelf mas balance processes in Antarctic circulation models. In the Amundsen Sea, the shoaling warm Circumpolar Deep Water (CDW) and surficial glacial meltwater are two important diagnostic and prognostic terms in the ice shelf mass balance. By measuring the distribution of these water masses, using a suite of their distinct inert gas tracers ? 3He, 4He, Ne, Ar, Kr and Xe - together with their change over time, estimates of basal melt rates of some of the large West Antarctic ice shelves (e.g. Pine Island Glacier) are to be made. Greenland and the West Antarctic Ice Sheets together represent potentially more than a 10 m of increase in mean (global) sea surface height. How fast glacial mobilization rates may increase is of considerable societal importance.

冰架质量平衡由净表面吸积（降水减去消融和表面融化项）、冰架空腔底部的崩解和基础融化控制，该空腔与变暖的海洋接触。估算基础融化速率是这种平衡中最具挑战性的一项，因为它很难直接观察，但对海洋温度和其他海洋-大气过程（例如海冰循环）的变化也很敏感。该项目将加入Ocean2ice该计划是英国牵头的一项工作，旨在整合最先进的仪器、化学分析和建模，其目标是改善南极环流模型中冰架质量平衡过程的动态表示。在阿蒙森海，浅滩温暖的环极深水（CDW）和表层冰川融水是冰架质量平衡中两个重要的诊断和预测术语。通过测量这些水团的分布，使用一套独特的惰性气体示踪剂？ 3He、4He、Ne、Ar、Kr 和 Xe - 连同它们随时间的变化，将对一些大型西南极冰架（例如松岛冰川）的基础融化速率进行估计。格陵兰岛和南极西部冰原的平均（全球）海面高度可能增加 10 m 以上。 冰川动员率增加的速度具有相当大的社会重要性。