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，是强烈的海气交换区域，也是世界海洋中吸收二氧化碳最强的区域之一。 然而，关于这种吸收的机制的基本问题仍然存在，部分原因是难以在这些动态区域进行持续的测量。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，可以测量低层大气和表面海洋特性，可以提供急需的新颖WBC观测策略。通过集成NOAA太平洋海洋环境实验室（PMEL）自主使用的最先进的CO2传感器，Saildrone可以提供一种潜在的变革性解决方案，以观察南半球远程和长期采样不足的WBC的海气通量。因此，拟议的工作是朝着关闭全球海洋碳预算迈出的重要一步。该项目还将包括对公众的一些外联活动。主要研究人员正在与罗得岛大学海洋项目办公室合作，协调一项公共活动，以配合在纽波特回收“帆船”无人机。她还计划访问当地的一所小学，与双语二年级学生一起做一个地图阅读练习，在这个练习中，他们选择一个Saildrone航点，并跟踪它的进展。这项研究的主要目标是使用Saildrone来测量冬季墨西哥湾流的表面热量和二氧化碳通量。由于其可变性的空间和时间尺度很短，WBC提出了Argo浮标测量无法解决的巨大观测挑战。 PMEL开发的最先进的自校准CO2传感器已经在系泊浮标上收集了数百天的气候质量数据，最近被改造用于Saildrone，初步任务表明它能够收集平台上的气候质量pCO 2数据（精确到2微气压）。 该项目的首席研究员最近获得了Saildrone奖，将在2019年冬季进行为期30天的穿越墨西哥湾流的使命。该RAPID项目为准备和集成自主水面车辆CO2传感器系统（ASVCO 2）的紧急任务提供资金。Saildrone的使命可以揭示，第一次，二氧化碳吸收沿着拉格朗日路径的墨西哥湾流相对于吸收模式水的形成过程中的重要性。墨西哥湾流也是测试Saildrone平台作为WBC海气通量观测战略的能力的理想区域，由于附近有观测资产，将提供独立的数据进行校准和验证，以及最近的冬季船舶-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。

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.