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

冰架物质平衡是由冰架底部的净表面增积(降水减去消融和表面融化项)、崩解和底部融化控制的，冰架空洞与变暖的海洋接触。在这一平衡中，估计基面融化速率是最具挑战性的术语，因为它很难直接观测，而且对海洋温度和其他海洋-大气过程的变化(如海冰周期)很敏感。该项目将加入海洋2ICE计划，该计划是英国领导的一项努力，旨在整合最先进的仪器、化学分析和模拟，目的是改善南极环流模式中冰架物质平衡过程的动态表示。在阿蒙森海，变浅的暖环极深水(CDW)和表层冰川融水是冰架物质平衡中的两个重要的诊断和预报术语。通过测量这些水团的分布，使用一套不同的惰性气体示踪剂--3He、4He、Ne、Ar、Kr和Xe--及其随时间的变化，可以估计一些大型西南极冰架(例如松岛冰川)的基本融化速度。格陵兰岛和西南极冰盖加在一起，意味着平均(全球)海面高度可能增加10米以上。冰川动员率增加的速度具有相当重要的社会意义。

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.