Collaborative Research: A new system for air-sea CO2 flux measurements from moored and unmanned surface platforms

合作研究：用于从系泊和无人水面平台测量海气二氧化碳通量的新系统

• 批准号: 1737184
• 负责人: Douglas Vandemark
• 金额: $ 27.42万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1737184&HistoricalAwards=false
• 关键词: Collaborative; Research; new; system; air

The oceans play a key role in the global carbon budget, currently absorbing roughly one quarter of anthropogenic CO2 emissions. The flux of CO2 across the air-sea interface is represented in models using an exchange coefficient or "transfer velocity" that is highly uncertain both in magnitude and spatial distribution, leading to uncertainty in current and future carbon budgets. The ability to measure air-sea CO2 exchange on short time scales over a broad range of ocean and atmospheric conditions is necessary to develop more accurate parameterizations of gas exchange with more realistic representation of physical processes affecting turbulence at the air-sea interface. This research aims to develop the capability to directly measure air-sea CO2 fluxes from buoys, with the potential to dramatically expand the database of direct flux measurements. If successful, this project will provide new capabilities for ocean time-series observations and the potential for incorporation into existing and future buoy-based ocean observing systems. These capabilities can adapt to other low-power, mobile platforms (spar buoys, catamarans, gliders) that will enable new observational approaches and insights into processes at a range of spatial and temporal scales. Future measurements enabled by this project also have the potential to impact broader policy by providing more accurate information for agencies and policy makers on how and where oceans take up and release carbon.This project will build and test the first CO2 flux measurement system that can be deployed on a buoy platform. The measurement approach utilizes the eddy covariance technique, which provides a direct flux measurement with high spatial (1-10 km2) and temporal (10-60 min) resolution. Previously, eddy covariance air-sea CO2 flux measurements have been restricted to research vessels, resulting in spatial and temporal limits on the collection of data that can be used to improve understanding of air-sea gas exchange. This research aims to develop the capability for robust, high-resolution, low-power, buoy-based CO2 flux measurements by directly addressing the primary technological obstacles to development of buoy-based eddy covariance CO2 flux systems: the small magnitude of the flux (poor signal-to-noise ratio), sensor performance limitations, low power availability, and harsh sampling conditions. Improvements to the sensor CO2 performance in collaboration with an instrument manufacturer will provide a clear pathway to commercialization and use by the broader oceanographic research community. The survivability and power-optimization challenges will be addressed by adapting the principle investigator?s experiences with both shipboard and buoy-based systems. The project will leverage ready access to extensive lab and field facilities that include ships, buoys, an indoor deep dive tank, and access to the Gulf of Maine for field work.

海洋在全球碳预算中起着关键作用，目前吸收了大约四分之一的人为CO2排放。使用交换系数或“转移速度”在模型中表示二氧化碳的通量在大小和空间分布上高度不确定，从而导致当前和未来的碳预算不确定。在广泛的海洋和大气条件下，在短时间尺度上测量空气二氧化碳交换的能力对于开发气体交换的更准确的参数化是必要的，并更真实地表示影响空气接口处湍流的物理过程。这项研究旨在开发直接测量浮标的空气二氧化碳通量的能力，并有可能显着扩展直接通量测量数据库。如果成功，该项目将为海洋时序观察提供新的功能，并有可能纳入现有和未来的基于浮标的海洋观测系统。这些功能可以适应其他低功耗的移动平台（Spar浮标，双体船，滑翔机），这些平台将使新的观察方法和洞察力对一系列空间和时间尺度的过程进行洞察力。该项目实现的未来测量还有可能影响更广泛的政策，通过为海洋如何以及在何处占据碳和释放碳的代理商和政策制定者提供更准确的信息。该项目将建立和测试可以成为的第一个CO2通量测量系统部署在浮标平台上。测量方法利用了涡流技术，该技术提供了高空间（1-10 km2）和时间（10-60分钟）分辨率的直接通量测量。以前，涡流协方差二氧化碳二氧化碳的测量局限于研究容器，从而在收集数据收集的空间和时间限制中，这些数据可用于提高对气海气交换的了解。这项研究旨在通过直接解决基于浮标的Eddy协方差二氧化碳系统的开发的主要技术障碍来发展稳健，高分辨率，低功率，基于浮标的二氧化碳通量测量的能力：磁通量很小（较小的大小）（信噪比差），传感器性能限制，低功率可用性和恶劣的采样条件。与仪器制造商合作的传感器二氧化碳性能的改进将为广泛的海洋研究社区提供明确的商业化和使用途径。通过调整主要调查员的经验以及基于浮标的系统的经验，将解决生存能力和功率优化挑战。该项目将利用现成的实验室和现场设施，包括船舶，浮标，室内深水罐，并进入缅因州湾进行现场工作。