Collaborative Research: Logistically Light Instrument Deployment for Estimation of Antarctic Basal Temperatures and Geothermal Heat Fluxes

合作研究：用于估算南极基础温度和地热热通量的后勤轻型仪器部署

• 批准号: 1542977
• 负责人: Dale Winebrenner
• 金额: $ 21.5万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1542977&HistoricalAwards=false
• 关键词: Collaborative; Research; Logistically; Light; Instrument

Title: Logistically Light Instrument Deployment for Estimation of Antarctic Basal Temperatures and Geothermal Heat FluxesNon-Technical Description: New observations of Antarctic ice sheet variables are essential for drill-site selection for climate records, for understanding how ice dynamics affect sea level, and for investigating the geologic history of the continent. Temperature depth-profiles are of particular current interest for estimating basal temperature and geothermal heat flux in Antarctica. Antarctic geothermal heat flux is presently poorly known except at recent drilling sites, and is the largest unknown in determining basal conditions. However, current logistical costs greatly limit drilling to acquire temperature profiles. Our long-term goal is the development, testing and commissioning of a new means of acquiring englacial temperature profiles at much lower costs than existing methods. To that end, we will undertake laboratory experiments and numerical modeling to develop to a new way to use ice melt probes, rather than traditional drilling, to deploy temperature measurement equipment to depths of a kilometer and greater. To use melt probes for this purpose, we must keep the melted ice above such probes from freezing completely, so that cable can be fed continually down to the probe as it descends. This development will also open the way toward recovering melt probes, so as to prevent environmental impacts and expense of equipment left in the field. Our initial experiments and modeling will test the validity of our approach and make it ready for further testing in the field. Technical Description: We will undertake laboratory and modeling work (1) to reduce the technical risk in our approach to melt-probe deployment of Raman Distributed Temperature Sensing (DTS) cables; and (2) to begin development of a recoverable ice melt probe. Specifically, we will use numerical modeling of the Stefan problem with cylindrical symmetry to guide detailed designs for cable-heating and anti-freeze injection, and will test and revise candidate designs by means of laboratory testing. We will test the long-term stability of ethanol-filled melt holes, to gauge their suitability for recoverable melt probe systems for temperature measurement (where months-long thermal equilibration after installation will be required). We will gain experience with Raman DTS methods by employing DTS to measure critical temperature data in our laboratory experiments, both within the melt hole and in adjacent ice. To address recoverability, we will design and test a new melt head for the upper end of our ice melt probe, and demonstrate upward travel through a partially refrozen melt hole. Finally, we will publish both modeling and experimental results in peer-reviewed publications, and will present the project to a broad public audience in a special event at a Seattle museum of science and technology. The result of this work will be demonstrated technical readiness for testing in a subsequent project at larger ice-drilling test facilities at the earliest opportunity (prospectively, at the University of Wisconsin, following soon after completion of this project) and, following that, in the field.

职务名称：非技术性描述：南极冰盖变量的新观测对于气候记录的钻探地点选择，对于理解冰动力学如何影响海平面，以及对于研究南极大陆的地质历史是必不可少的。温度深度剖面图目前对估计南极洲的基底温度和地热通量特别有意义。除了最近的钻探地点外，目前对南极地热通量知之甚少，并且是确定基础条件的最大未知数。然而，目前的物流成本大大限制了获取温度分布的钻井。我们的长期目标是开发、测试和调试一种新的方法，以比现有方法低得多的成本获得冰内温度分布。 为此，我们将进行实验室实验和数值模拟，以开发一种新的方法，使用融冰探针，而不是传统的钻探，将温度测量设备部署到一公里或更深的深度。 为此目的使用融化探头，我们必须保持探头上方的融化冰不完全冻结，以便电缆可以在探头下降时连续向下馈送。 这一发展也将为回收熔融探针开辟道路，以防止环境影响和现场遗留设备的费用。 我们的初步实验和建模将测试我们的方法的有效性，并使其准备在该领域的进一步测试。 技术说明：我们将进行实验室和建模工作，以（1）降低我们部署拉曼分布式温度传感（感温）电缆的方法中的技术风险;（2）开始开发可回收的融冰探头。具体来说，我们将使用数值模拟的斯特凡问题与圆柱对称，以指导电缆加热和防冻注射的详细设计，并将测试和修改候选设计通过实验室测试。 我们将测试填充乙醇的熔孔的长期稳定性，以衡量其对用于温度测量的可回收熔针系统的适用性（安装后需要数月的热平衡）。 我们将获得经验，拉曼拉曼光谱方法，采用拉曼光谱测量临界温度数据在我们的实验室实验中，无论是在融化的洞，并在邻近的冰。为了解决可回收性，我们将设计和测试一个新的融化头的上端，我们的冰融化探头，并证明向上旅行通过一个部分再冻结融化孔。 最后，我们将在同行评议的出版物上发表建模和实验结果，并将在西雅图科技博物馆的一个特别活动中向广大公众展示该项目。 这项工作的结果将证明技术准备在随后的项目测试在更大的冰钻测试设施在最早的机会（前瞻性地，在威斯康星州大学，在该项目完成后不久），并在此之后，在现场。