EAGER: Feasibility of Reconstructing the Atmospheric History of Molecular Hydrogen from Antarctic Ice

氢(H2)是大气中含量最丰富的痕量气体之一，平均水平为500 ppb，大气寿命约为两年。氢对空气质量和气候都有影响，因为它是对流层臭氧和平流层水蒸气的前体。预测表明，未来的“氢经济”将增加氢排放。对大气氢收支的了解在很大程度上是基于地面空气测量的30年记录，但没有长期记录来评估：1)气候变化对大气氢收支的影响，或2)人类对氢收支的影响程度。极地冰芯对氢的记录将促进我们对大气氢循环的理解，并为预测未来大气氢水平的变化及其影响提供更有力的基础。这项研究将涉及实验室工作，以便能够收集和分析极地冰芯中的氢。氢是一种高度扩散的分子，与大多数其他大气气体不同，氢在冰中的扩散如此之快，以至于冰样必须在钻探和回收后立即储存在不透水的容器中。该项目将：1)建立一个提取和分析极地冰中氢的实验室系统；2)开发和测试用于现场存储冰芯样品的船只的材料和结构设计；3)在以前存储在现场的机会样品上测试该方法。该项目的目标是为未来的极地冰芯项目制造一种经过验证的、具有成本效益的存储烧瓶设计。该项目将支持加州大学欧文分校地球系统科学系一名研究生的论文研究。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Hydrogen (H2) is one of the most abundant trace gases in the atmosphere, with a mean level of 500 ppb and an atmospheric lifetime of about two years. Hydrogen has an impact on both air quality and climate, due to its role as a precursor for tropospheric ozone and stratospheric water vapor. Projections indicate that a future "hydrogen economy" would increase hydrogen emissions. Understanding of the atmospheric hydrogen budget is largely based on a 30-year record of surface air measurements, but there are no long-term records with which to assess either: 1) the influence of climate change on atmospheric hydrogen, or 2) the extent to which humans have impacted the hydrogen budget. Polar ice core records of hydrogen will advance our understanding of the atmospheric hydrogen cycle and provide a stronger basis for projecting future changes to atmospheric levels of hydrogen and their impacts. The research will involve laboratory work to enable the collection and analysis of hydrogen in polar ice cores. Hydrogen is a highly diffusive molecule and, unlike most other atmospheric gases, diffusion of hydrogen in ice is so rapid that ice samples must be stored in impermeable containers immediately upon drilling and recovery. This project will: 1) construct a laboratory system for extracting and analyzing hydrogen in polar ice, 2) develop and test materials and construction designs for vessels to store ice core samples in the field, and 3) test the method on samples of opportunity previously stored in the field. The goal of this project is a proven, cost-effective design for storage flasks to be fabricated for use on future polar ice coring projects. This project will support the dissertation research of a graduate student in the UC Irvine Department of Earth System Science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.