NNA: AON: EAGER: Closing the Water Vapor Exchange Budget Between the Ice Sheets and Free Atmosphere

随着北极变暖的速度比地球上其他地方快，了解格陵兰冰盖对气候变化的反应？以及对海平面上升的相关影响，对政策和减缓战略至关重要。目前存在各种卫星和地面工具，以帮助了解积雪和冰从出口冰川或融化的损失，但内部冰盖和大气之间的水蒸气交换的大小仍然基本上是未知的。在计算冰盖的质量增加或损失时，这种蒸汽通量可能是一个非常大的因素。 蒸汽通量的产生要么是由于蒸汽沉积和冷凝而增加到冰表面，要么是由于升华而损失。该项目旨在利用无人驾驶航空器（通常称为无人机）收集大气水蒸气样本，以限制格陵兰冰盖上的蒸气通量。 一个包含多个空气捕获室和环境传感器的遥控采样舱将被改装成一架商用多直升机无人机，并在冰面上方飞行以收集样本。着陆后，将对大气样本进行水同位素分析，水同位素是具有不同分子量的水分子的变化，例如，可以提供蒸汽流入或流出冰盖的证据。该项目的目标是利用无人机捕获的数据来解决对格陵兰冰盖冻结水储存的理解方面的主要差距，这可能会减少全球海平面上升估计的不确定性。这些数据还可用于改进用于高纬度水同位素测量的卫星算法;改进大气环流模型;以及提高对大气的总体气象学认识。此外，这些数据也可以证实目前的理解长期温度记录恢复从水同位素的极地冰芯。使用无人机采样装置的初步测试和大气测量将于2018年夏季在格陵兰岛东北部的一个冰芯营地进行。2019年的第二次部署将允许改进无人机采样单元，并可能部署一架固定翼无人机，用于测量整个4个月夏季野外季节的高分辨率数据。该项目将导致第一架改装有水蒸气采样吊舱的无人机，可以在飞行后直接在现场进行分析。在这样做的过程中，该项目将提供格陵兰冰盖上方关键大气边界层中水蒸气同位素的第一个详细和高分辨率的空中测量。这个区域对于载人飞行任务来说通常过于昂贵和危险，气球释放实验已经证明后勤负担沉重，科学回报有限。这项研究汇集了来自航空航天工程和地球化学领域的研究人员。 学生和研究人员将通过联邦航空管理局认证的课程接受无人机飞行员培训。 本科生和研究生将接受实验室培训，以协助处理和解释数据。在外地行动期间，将提供一个供公众浏览和外联的近实时博客，其中将包括外地最新情况、选定数据、照片和影片。公开讲座和科学讲座将进一步传播在该项目期间学到的知识。随着该项目技术的进步，它可以被转移到其他项目，如检测油气威尔斯的逃逸排放或测量融化的永久冻土地区的甲烷释放。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

As the Arctic warms faster than the rest of the planet, understanding the Greenland ice sheet response to changing climate ? and the associated effect on sea level rise - is important for policy and mitigation strategies. A variety of satellite and surface tools currently exist to help understand snow accumulation and the loss of ice from outlet glaciers or melting, but the magnitude of water vapor exchange between the interior ice sheet and the atmosphere remains essentially unknown. This vapor flux could potentially be a very large factor in calculating the mass gain or loss of the ice sheet. Vapor flux occurs either by addition to the ice surface through vapor deposition and condensation or losses due to sublimation. This project seeks to utilize Unmanned Aerial Vehicles, commonly referred to as drones, for collecting atmospheric water vapor samples to constrain vapor flux on the Greenland Ice Sheet. A remote-controlled sampling pod containing multiple air-capture chambers and environmental sensors will be retrofitted to a commercially available multi-copter drone and flown above the ice surface to collect samples. Upon landing, the atmospheric samples will be analyzed for water isotopes, which are variations of water molecules with different molecular weights that can, for example, provide evidence of vapor flux into or away from the ice sheet. The goal of this project is to use drone-captured data to address major gaps in the understanding of frozen water storage on the Greenland ice sheet, which could reduce uncertainty in estimates of global sea level rise. The data can also be used to improve satellite algorithms used for high-latitude measurements of water isotopes; to improve general circulation models; and improve meteorological understanding of the atmosphere in general. Further, these data may also substantiate the current understanding of long-term temperature records recovered from water isotopes of polar ice cores. Initial testing and atmospheric measurements using the drone-sampling unit will occur in Summer 2018 at an ice core camp in Northeast Greenland. A second deployment in 2019 will allow for improvements to the drone-sampling unit, and a possible deployment of a fixed wing drone aircraft, for measurement of high-resolution data across the 4-month summer field season. This project will result in the first drone retrofitted with a water vapor sampling pod, which can be directly analyzed in the field following flight. In doing so, the project stands to provide the first detailed and high-resolution airborne measurements of water vapor isotopes in the critical atmospheric boundary layer just above the Greenland Ice Sheet. This region is typically too expensive and dangerous for manned-flight missions, and balloon release experiments have proven logistically burdensome with limited scientific returns. This study brings together researchers from the fields of Aerospace Engineering and Geochemistry. Students and researchers will receive drone pilot training through a Federal Aviation Administration accredited class. Undergraduate and graduate students will receive laboratory training to assist in processing and interpreting the data. A near real-time blog for public viewing and outreach will be available during field operations, which will include field updates, selected data, photography, and film. Public lectures and scientific talks will further disseminate the knowledge learned during this project. As the technology for this project progresses, it could be transferred to other projects, such as detection of fugitive emissions from oil and gas wells or to measure methane release in regions of thawing permafrost.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.