Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater

利用海水稳定同位素分析估算南极冰融化量

• 批准号: 1644118
• 负责人: Robert Dunbar
• 金额: $ 56.97万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1644118&HistoricalAwards=false
• 关键词: Estimation; Antarctic; Ice; Melt; using; Estimation; Antarctic; Ice; Melt; using

Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt.This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.

估计南极冰盖生长或损失对于预测未来的海平面上升至关重要。 这样的估计依赖于现场测量值或对冰盖表面，冰缘和 /或冰架的基于远程感知的观察结果。这项工作研究了将淡水引入海洋到周围的南极洲，以追踪大陆冰的融水。 相对于南部海水和降水量，极地冰耗尽了两个稳定的同位素，18o和d，氘。与海水温度和盐度的精确观察结合的海水同位素组成的测量将允许歧视淡水源自区域降水或海冰融化的冰川冰的融化冰冰。这项研究描述了一种可接受的方法，用于确定从极性冰层融化海洋的速率和位置。由于在许多南极沿海海中的同位素和盐度扰动是累积的，该方法允许在特定区域中检测到融合水中的任何明显加速度，使用在数年隔一段时间内收集和分析的样品。该项目的影响来自使用一种独立方法，能够限制有关当前冰盖融化速率的知识，其稳定性以及对海平面上升的潜在影响。该项目允许从南极水上航行的外国船只采集样本，然后分享和解释数据。研究伙伴包括美国，韩国，中国，新西兰，英国和德国。参与的合作者将在斯坦福大学收集海水样本进行同位素和盐度分析。 USAP巡航将集中于对罗斯海和西南西部进行采样。工作计划包括使用框模型和混合曲线分析以及使用启用同位素的ROM（区域海洋建模系统）模型的同位素数据的解释。 研究的更广泛的影响将包括开发一个教育模块，该模块说明了科学方法以及海洋观察如何帮助社会了解地球的变化。