EAGER: A low-cost, long-endurance observational platform for the Arctic atmospheric boundary layer

北极是地球上变化最快的环境。自20世纪70年代以来，该地区的气温上升了3摄氏度以上，比全球平均水平快三倍。在过去的几十年里，北极已经为气候变化扮演了煤矿中金丝雀的角色，但我们在这个恶劣而偏远的地区监测大气的能力仍然非常有限，并且经常依赖于非常昂贵的载人飞行和研究巡航。这与海洋的情况形成鲜明对比，自主平台提供了丰富的观测。由此造成的观测数据的缺乏阻碍了我们对北极演变及其与低纬度天气和全球气候关系的理解。该项目的重点是通过设计、开发和测试一个新的观测平台来克服目前在监测北极大气方面的挑战，该平台旨在提供全天候对北极中部的自主、连续的访问。EAGER项目支持设计、测试和实施一个自主的北极大气观测系统，该系统使用一种新设计的气球，每次部署都能进行多次探测。该平台的使命要求包括：i）在盛行风的作用下飞越北极盆地，同时在三周内每天进行四次1公里的探测; ii）在-50 ° C和+20 ° C之间的温度范围内运行; iii）在降水和结冰中生存。通过进行一系列台架测试和两次实地活动，该项目将重点验证三个假设。首先，所提出的机械压缩气球设计将提供足够的机动性和鲁棒性，以经受恶劣天气的影响。第二，传感器、卫星调制解调器和高比能电池的最新进展将在重量和能耗方面提供足够的节省，以实现三周的飞行时间目标。第三，可以设计一种控制算法，使几个平台以节能的方式自主飞越北极。该项目还将支持教育和公共宣传，通过示范活动，使用按比例缩小气球部署。这个奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

The Arctic is the fastest-changing environment on the planet. Temperatures in the region have risen by more than 3°C since the 1970s, three times faster than the global average. Over the past few decades, the Arctic has taken the role of a canary in the coal mine for climate change, but our ability to monitor the atmosphere in this harsh and remote region is still very limited, and often relies on very expensive manned flights and research cruises. This is in contrast with the situation in the ocean, where autonomous platforms have provided a wealth of observations. The resulting paucity of observations is hindering our understanding of the Arctic evolution, and of its relationship to lower latitude weather and the global climate. This project focuses on overcoming current challenges in monitoring the Arctic atmosphere by designing, developing, and testing a novel observational platform aimed at providing autonomous, continuous access to the central Arctic throughout all seasons.This EAGER project supports the design, testing and implementation of an autonomous Arctic atmospheric observing system using a novel design of balloons capable of making multiple soundings for each deployment. The platform’s mission requirements include the ability to: i) fly across the Arctic basin carried by the prevailing winds while performing four, 1 km soundings per day over three weeks; ii) operate within a temperature range between -50°C and +20°C; and iii) survive precipitation and icing. By performing a series of bench tests and two field campaigns, the project will focus on verifying three hypotheses. First, that the proposed mechanical-compression balloon design will provide sufficient maneuverability and robustness to survive the impact of inclement weather. Second, that recent advancements in sensors, satellite modems, and high-specific-energy batteries, will provide sufficient savings in weight and energy consumption to achieve the target three-week flight time. Third, that a control algorithm can be designed to autonomously fly several platforms across the Arctic in an energy efficient way. The project will also support education and public outreach through demonstration events using scaled-down balloon deployments.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.