Estimating the Salinity of Subglacial Lakes From Existing Aerogeophysical Data

STUDING/0636584该奖项支持一个项目，该项目利用现有的机载穿冰雷达和激光高度计数据估计冰下沃斯托克湖、康科迪亚湖和90°E湖的盐度。之所以选择这些湖泊，是因为可以获得现代航空地球物理数据，而且它们足够大，使得浮冰不会受到接地线附近边界应力的影响。所提出的方法是基于这样的假设，即大型冰下湖泊上方的冰盖处于流体静力平衡状态，湖水的密度和随后的盐度可以根据冰面高度和浮冰厚度之间的(线性)关系来估计。拟议工作的目标是估计沃斯托克湖的盐度，确定空间变化，并比较东南极3个大型冰下湖泊的盐度估计。该项目的学术价值在于，这项工作将有助于了解在冰川下湖泊环境中运行的物理和化学过程。由于无法进入冰下湖泊，目前只有对水循环进行数值模拟，才能从概念上了解冰下湖泊的循环、融化和冻结状态。数值实验表明，湖水盐度是三维流体动力学模型的重要输入参数。改进的数值模型将有助于我们了解冰下湖泊中的水循环，它对水和热收支、分层、融化和冻结的影响，以及在这种极端环境中支持生命的条件。该项目的更广泛影响是，冰下湖泊吸引了许多人、科学家和门外汉的兴趣。国内和国际媒体经常报道首席调查员的研究情况。他的沃斯托克湖插图已被用于数学和地球科学教科书。沃斯托克湖将用于地球课堂项目的教育和推广。Earth2Class是一个非常成功的科学/数学/技术学习资源，适用于纽约大都市区的K-12学生、教师和管理人员。Earth2Class是由拉蒙特-多尔蒂地球天文台的研究科学家、哥伦比亚大学师范学院的课程和教育技术专家以及纽约大都市区的课堂教师合作创建的。

Studinger/0636584This award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake's water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake's water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.