Collaborative Research: Developing a profiling glider pH sensor for high resolution coastal ocean acidification monitoring

海洋酸化具有重大的科学和社会影响，包括海洋生物地球化学的改变、与生态系统改变相关的生态后果以及具有重要商业价值的生物生存减少造成的经济损失。然而，很少有时间序列和高分辨率的空间和时间测量来跟踪低pH和低碳酸盐饱和度水的存在和运动，特别是在鱼类、龙虾和野生贝类种群所在的沿海地区。过去的海洋酸化监测工作(带有pH的表层浮标或测量二氧化碳分压或二氧化碳分压的传感器、科考船使用的流通式二氧化碳分压系统、大型实地活动期间的水柱采样)要么空间分辨率低(系泊)，要么成本高、时间和空间分辨率低(研究巡航)。因此，迫切需要部署新的、具有成本效益的技术，这些技术可以常规地在我们沿海海洋的区域尺度上提供高分辨率的水柱OA数据。事实证明，自主水下仿形滑翔机是一种履行这一角色的强大技术。各种传感器已经成功地安装在Slocum滑翔机上；然而，安装在这些滑翔机上的pH传感器没有收集到海洋pH值的直接测量结果。研究人员将开发集成的滑翔机平台和传感器系统，在区域范围内对沿海海洋水柱中的pH和可能的高温进行采样。该项目将产生一种新的商业上可用的滑翔机pH传感器套件，它将为一个能够为广泛用户服务的实时国家沿海办公自动化监测网络奠定基础。此外，在一架滑翔机上集成来自多个传感器的同时测量将使人们能够区分生态系统的物理、化学和生物之间的相互作用。研究人员将修改和集成基于离子敏感场效应晶体管(ISFET)的深度额定版本的pH传感器，即深海DuraFET pH传感器系统，并将其集成到Slocum滑翔机中。他们将通过在美国东北大陆架部署三架滑翔机来测试新的传感器套件，实时提供OA数据，并检查具有商业重要性的渔业栖息地的pH/温度动态。该项目将通过协调高分辨率滑翔机绘制的pH和并排NOAA OAP(海洋酸化计划)计划的ECOA(东海岸海洋酸化)第二次巡航而受益于严格的地面测量，在那里将测量全套碳酸盐参数(二氧化碳、pH、溶解无机碳、总碱度和氧)，无论是正在进行中还是在船上测量。将在美国东北部大陆架具有重要商业意义的渔业栖息地提供高空间和时间分辨率的现场pH测量和估计。这些开放的、自动化的实时数据将通过RUCOOL(罗格斯大学海洋观测领导中心)、MARACOOS(中大西洋区域协会沿海海洋观测系统)和THREDDS(专题实时环境数据分发系统)提供。这项新技术产生的数据将使研究人员和社区能够跟踪低pH/高温水的运动，了解pH/高温的变化，预测混合事件和循环将如何影响整个大陆架的pH/高温，识别更容易出现pH/高温降低的商业重要物种的高风险区域和种群，最终将使未来更酸性的海洋能够更明智地管理基本栖息地。

Ocean acidification (OA) has significant scientific and societal ramifications including the alteration of ocean biogeochemistry, ecological consequences associated with altered ecosystems, and economic losses due to the decreased survival of commercially important organisms. Yet few time series and high resolution spatial and temporal measurements exist to track the existence and movement of low pH and low carbonate saturation (Ù) water, specifically in coastal regions where finfish, lobster, and wild stocks of shellfish are located. Past ocean acidification monitoring efforts (surface buoys with pH or sensors that measure partial pressure of carbon dioxide, or pCO2, flow-through pCO2 systems utilized by research vessels, water column sampling during large field campaigns) have either low spatial resolution (mooring) or high cost and low temporal and spatial resolution (research cruises). Therefore, there is a critical need to deploy new, cost-effective technologies that can routinely provide high resolution water column OA data on regional scales in our coastal ocean. Autonomous underwater profiling gliders have proven to be a robust technology that fulfills this role. A variety of sensors have successfully been mounted on Slocum gliders; however, no direct measurements of ocean pH have been collected by pH sensors mounted on these gliders. The researchers will develop the integrated glider platform and sensor system for sampling pH and possibly Ù in the water column of the coastal ocean on a regional scale. This project will result in a new commercially available glider pH sensor suite that will provide the foundation of what could become a real-time national coastal OA monitoring network with the capability of serving a wide range of users. Additionally, the integration of simultaneous measurements from multiple sensors on one glider will allow one to distinguish interactions between the physics, chemistry, and biology of the ecosystem. The researchers will modify and integrate a deep rated version of the Ion Sensitive Field Effect Transistor (ISFET)-based pH sensor, the Deep-Sea DuraFET pH sensor system, into a Slocum glider. They will test the new sensor suite via three glider deployments on the U.S. Northeast Shelf, deliver the OA data in real-time, and examine pH/Ù dynamics in habitats of commercially important fisheries. The project will benefit with rigorous groundtruthing via coordination of the high resolution glider mapping of pH and Ù side-by-side NOAA OAP's (Ocean Acidification Program) planned ECOA (East Coast Ocean Acidification) cruise II where a full suite of carbonate parameters (pCO2, pH, dissolved inorganic carbon, total alkalinity, and oxygen) will be measured either underway or on board ship. High spatial and temporal resolution in situ pH measurements and Ù estimations will be provided in habitats of commercially important fisheries in the U.S. Northeast Shelf. This open accessible, automated real-time data will be made available through RUCOOL (Rutgers University Center for Ocean Observing Leadership), MARACOOS (Mid-Atlantic Regional Association Coastal Ocean Observing System), and THREDDS (Thematic Real-time Environmental Data Distribution System). The data produced from this new technology will allow the researchers and the community to track the movement of low pH/Ù water, understand the variability of pH/Ù, predict how mixing events and circulation will impact pH/Ù across the shelf, identify high-risk regions and populations of commercially important species that are more prone to periods of reduced pH/Ù, and ultimately will enable more informed management of essential habitats in the future, more acidic oceans.