RAPID: Observing Heat and Carbon Fluxes with an Autonomous Wind-powered Surface Vehicle in the Gulf Stream

西部边界流(WBC)，如墨西哥湾流，是世界海洋中海气交换强烈和二氧化碳吸收最强的地区。然而，关于管理这种吸收的机制仍然存在基本问题，部分原因是在这些动态地区进行持续测量的难度。该项目将证明，Saildrone是一种快速移动(3-5节)、高耐力(超过3个月)的自主表面平台，可以测量较低的大气和表面海洋属性，可以提供亟需的新的WBC观测战略。Saildrone集成了NOAA太平洋海洋环境实验室(PMEL)为自主使用而设计的最先进的二氧化碳传感器，可以作为一种潜在的变革性解决方案来观测南半球偏远和长期采样不足的WBC的海气通量。因此，拟议的工作是朝着结束全球海洋碳预算迈出的重要一步。该项目还将包括一些面向普通公众的宣传活动。首席调查员正在与罗德岛大学海洋项目办公室合作，协调一项公共活动，以配合在纽波特找回无人驾驶帆船的活动。她还计划访问当地一所小学，在双语二年级的情况下进行一次地图阅读练习，在练习中，他们选择一个Saildrone路线并跟踪其进展情况。这项研究的主要目标是使用Saildrone测量冬季墨西哥湾流的表面热量和二氧化碳通量。由于其变异性的空间和时间尺度短的特点，WBC带来了巨大的观测挑战，这是Argo浮标测量无法解决的。PMEL开发的一种最先进的自校准二氧化碳传感器已经在系泊浮标上收集了数百天的气候质量数据，最近被改装用于帆船无人机，初步任务表明，它能够在平台上收集气候质量二氧化碳数据(精确度为2微ATM)。该项目的首席研究员最近获得了帆船奖，将在2019年冬季执行为期30天的穿越墨西哥湾流的任务。这一快速项目为准备和集成自主水面车辆二氧化碳传感器系统(ASVCO2)的紧迫任务提供了资金，以便及时部署。Saildrone任务可以首次揭示沿墨西哥湾流拉格朗日路径的二氧化碳吸收相对于模式水形成过程中的吸收的重要性。墨西哥湾流也是测试Saildrone平台作为WBC海气通量观测战略能力的理想区域，因为附近有观测资产，将为校准和验证提供独立数据，最近的冬季船基通量调查为比较提供有价值的数据。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。

Western Boundary Currents (WBCs) such as the Gulf Stream are regions of intense air-sea exchange and some of the strongest CO2 uptake in the world ocean. Yet basic questions persist about the mechanisms governing this uptake, partly because of the difficulty of making sustained measurement in these dynamic regions. This project will demonstrate that Saildrone, a fast-moving (3-5 knots), high-endurance (over 3 months) autonomous surface platform that measures lower atmosphere and surface ocean properties, can provide a much-needed, novel WBC observing strategy. With the integration of a state-of-the-art CO2 sensor designed for autonomous use by NOAA's Pacific Marine Environment Lab (PMEL), Saildrone could provide as a potentially transformative solution to observing air-sea fluxes across the remote and chronically-undersampled WBCs of the Southern Hemisphere. Thus, the proposed work is an important step toward closing the global ocean carbon budget. The project will also include some outreach to the general public. The principal investigator is working with the University of Rhode Island Office of Marine Programs to coordinate a public event to coincide with the recovery of the Saildrone in Newport. She also plans to visit a local elementary school to do a map-reading exercise with a bilingual second grade, in which they pick a Saildrone waypoint and track its progress toward it.The main goal of this study is to use Saildrone to measure wintertime surface heat and CO2 fluxes across the Gulf Stream. Because of the short space and time scales characterizing their variability, WBCs present tremendous observing challenges that are not addressed with Argo float measurements. A state-of-the-art, self-calibrating CO2 sensor developed by PMEL has collected climate-quality data for hundreds of days on moored buoys, was recently adapted for use on the Saildrone, and preliminary missions show that it is capable of collecting climate quality pCO2 data (accurate to 2 micro atm) aboard the platform. The principal investigator of this project recently won the Saildrone award to sail a 30-day mission across the Gulf Stream in winter 2019. This RAPID project funds the urgent task of preparing and integrating the Autonomous Surface Vehicle CO2 sensor system (ASVCO2) in time for the deployment. The Saildrone mission can reveal, for the first time, the importance of CO2 uptake along the Lagrangian pathway of the Gulf Stream relative to uptake during mode water formation. The Gulf Stream is also an ideal region to test the capability of the Saildrone platform as a WBC air-sea flux observing strategy, as there are nearby observing assets that will provide independent data for calibration and validation and a recent wintertime ship-based flux survey to provide valuable data for comparison.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.