Calibrated pCO2 in air and surface ocean Sensor for ASVs (CaPASOS)

用于 ASV (CaPASOS) 的空气和海洋表面校准 pCO2 传感器

• 批准号: NE/P020801/1
• 负责人: Matt Mowlem
• 金额: $ 54.99万
• 依托单位: NATIONAL OCEANOGRAPHY CENTRE
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP020801%2F1
• 关键词: Calibrated; pCO2; air; surface; ocean

The human emission of carbon dioxide, largely from fossil fuel burning, will continue for the foreseeable future to be the most important cause of climate change. Only about half of our emissions are remaining in the atmosphere however. The other half is being absorbed, it is believed, in approximately equal amounts by vegetation on land and uptake by the ocean. These "natural sinks" of CO2 are consequently of huge value to us, since they slow the progress of climate change, so their present operation, and possible changes future uptake of CO2, are a focus of intense research. The sink of CO2 into the ocean is today being observed by measurements of atmospheric and sea surface pCO2, the partial pressure of CO2 at the surface of the ocean. This controls the rate at which CO2 exchanges between the ocean and atmosphere, and which for this reason has been designated an "essential ocean variable" by the Global Ocean Observing System. These observations are usually made from commercial vessels, and where there are busy shipping routes, for example in much of the Atlantic and North Pacific Oceans, there are sufficient observations to describe the air-sea flux. However, there are other very large regions (the Indian, South Pacific and Southern Oceans for example) where we have woefully insufficient data. In the future, this need could be met by autonomous surface vehicles (ASVs) making pCO2 measurements, and our proposal is to develop a pCO2 sensor specifically designed for ASVs. It will follow protocols that have been established by international bodies for the highest quality measurements suited to calculating the air-sea flux of carbon dioxide in the open ocean. The technical challenge is to adapt the successful principles of the instruments mounted in ships or on large buoys, where space and power are not limiting factors, to achieve the same high accuracy with small space and power footprint, resistance to violent motion, and long endurance, necessary on an ASV. We will achieve this by bringing together the extensive experience that the Exeter University group has in operating ship-based CO2 systems over 20 years, with improvements in engineering, utilising the experience and expertise of the NOC Technology and Engineering groups. We will use the basic measurement technique that has been well tested on the large instruments (equilibration of water with gas, and measurement of CO2 in gas by non-dispersive infra-red detection). However, we will use miniaturised components having small volumes and low flow rates of gas, enabling even a small instrument to carry on-board calibration gases. The specifications of the final instrument will include: endurance of up to a year and with frequency of measurements (both surface water and atmosphere) sufficient to define daily cycles, regular calibration using on-board calibration gases stored in miniature compressed gas cylinders, and measurement of CO2 in dried air which has equilibrated with surface water by direct contact. The instrument will also conform to data standards and integration protocols to enable the ready integration and exchange of sensors into autonomous platforms.A laboratory prototype exists, built by U. Exeter. To achieve our main objective, our sub-objectives are: 1) Development of second generation and deployment alongside a shipboard instrument and testing at coastal sites (2) modification and deployment on a mooring at the Western Channel Observatory for an extended period (3) Construction of third generation with attention to each component of the system to optimise performance and robustness, (4) integration into an ASV, (5) extensive sea testing (e.g. on the "MASSMO" exercises, experimental missions of autonomous marine vehicles conducted regularly around UK waters, and on research cruises.

在可预见的将来，二氧化碳的人类排放将继续是气候变化的最重要原因。但是，只有大约一半的排放位于大气中。据信，另一半正在吸收，植被在陆地上的植被和海洋吸收大约相等。因此，这些二氧化碳的“天然水槽”对我们来说是巨大的价值，因为它们减缓了气候变化的进步，因此他们目前的运营以及可能改变未来二氧化碳的吸收，这是激烈研究的重点。如今，通过大气和海面PCO2的测量，二氧化碳进入海洋，这是二氧化碳在海洋表面的部分压力。这控制了二氧化碳在海洋和大气之间交换的速度，因此，全球海洋观察系统已将其指定为“基本海洋变量”。这些观察结果通常是由商业船只制成的，在繁忙的运输路线（例如在大西洋和北太平洋的大部分地区）中，有足够的观察值来描述空气海量助焊剂。但是，还有其他非常大的地区（例如，印度，南太平洋和南大洋），我们的数据不足。将来，可以通过对PCO2进行测量的自动表面车辆（ASV）来满足这一需求，而我们的建议是开发专门为ASV设计的PCO2传感器。它将遵循国际机构建立的方案，用于用于计算公海中二氧化碳的空气通量的最高质量测量。技术挑战是要适应安装在船上或大型浮标上的工具的成功原理，因为空间和力量不是限制因素，以实现相同的高精度，而在ASV上必不可少。我们将通过将埃克塞特大学（Exeter University Group）在20年内运行基于船舶的二氧化碳系统的丰富经验汇集在一起​​，并利用NOC技术和工程小组的经验和专业知识来实现​​这一目标。我们将使用已经在大型仪器上进行了经过良好测试的基本测量技术（水与气体的平衡，以及通过非分散性的红外检测对CO2的测量）。但是，我们将使用具有较小体积和低流量的微型组件，即使是小型仪器也能够携带船上校准气体。最终仪器的规格将包括：长达一年的耐用性以及足以定义每日周期的测量频率（地表水和大气），使用板载校准气体存储在微型压缩气缸中的定期校准，以及在直接接触地表水与地表水平的二氧化碳中测量的二氧化碳。该仪器还将符合数据标准和集成协议，以使传感器现成的集成和交换为自主平台。为了实现我们的主要目标，我们的亚物品是：1）第二代和部署以及在沿海地点进行的船舶仪器以及测试（2）在西部频道观测站进行修改和部署，以长期（3）第三代构造（3）对系统的每个组件的关注，以优化质量和稳健性，（4）E.（4）E.（4）（4）（4）（4）（4）（5）（5）（5）（5）（5）（5）（5）（5）练习，经常在英国水域周围进行的自动驾驶汽车的实验任务以及研究巡游。