Quantifying the surface physical controls on CO2 transfer during the Southern Ocean Gas Exchange Experiment

通过空气-水界面的气体通量率的量化问题是海洋学的核心问题之一，在温室气体和海洋-大气预算的背景下是至关重要的。大气和海洋之间二氧化碳通量的巨大不确定性使我们无法确定海洋和陆地生物圈之间人为二氧化碳汇的分配情况。这种不确定性也限制了我们实际模拟未来大气二氧化碳水平的能力。国际SOLAS（表层海洋？）低层大气研究的科学计划和实施战略强调了提高对气体交换理解的必要性。如计划所述？[SOLAS]重点2的目标是发展对负责质量、动量和能量的海气交换过程的定量认识，以便精确计算区域和全球气体和气溶胶通量。这就需要确定这些界面传递机制对大气和海洋边界层内的物理、生物和化学因素的依赖性。在这个项目中，迈阿密大学罗森斯蒂尔海洋与大气科学学院的研究人员将对南大洋的海气二氧化碳交换测量进行一套独特的测量，作为即将到来的？南大洋天然气交换？(SOGasEx)实验。SOGasEx（也称为GasEx III）设计用于进行这些测量，并确定大风时控制海气交换的因素。迈阿密研究小组希望通过其独特的能力来增强主要基于船舶的SOGasex测量，从而在自主平台上进行高分辨率的海空界面测量。具体来说，他们将部署一个新的极端海气相互作用（EASI）浮标，用于测量二氧化碳、气溶胶、感热和潜热、动量的直接通量，以及基本的气象和海洋参数（风速、稳定性、气温、湿度、海温等），以及一个海气相互作用Spar （ASIS）浮标，用于测量控制表面物理过程（表面波，包括斜坡、洋流、上层海洋湍流和混合）。由于水流扭曲等原因，许多测量无法在高浪环境下的船上进行，因此需要自主平台。此外，他们将使用安装在船上的摄像机/视频系统测量白帽覆盖率。通过这些测量，我们希望进一步了解与大风过程相关的气体传递过程。就更广泛的影响而言，这项工作涉及提高我们预测大气二氧化碳水平的能力，并评估它们在各种情况下如何改变气候。气候变化正成为各国政府面临的最具挑战性的政策问题之一。我们目前缺乏对海气传输速率的充分参数化，直接导致我们无法确定地预测大气中二氧化碳和其他与气候有关的化合物的未来浓度。这项研究预计将提高全球海洋二氧化碳通量估计的准确性，并增加我们对其变率原因的了解。拟议的测量采用最先进的仪器，这将增强SOGasEx实验。有机会参加这一实验，并获得用于后续分析的数据，将提供一个独特的数据集，从而增加我们对海气二氧化碳交换在影响气候方面的作用的了解。

The problem of quantifying the rate of gas flux across the air-water interface is one of the central questions of oceanography and is critical in the context of greenhouse gases and ocean-atmosphere budgets. The large uncertainty surrounding the flux of CO2 between the atmosphere and ocean prevent us from determining the partitioning of the sink of anthropogenic CO2 between the ocean and the terrestrial biosphere. This uncertainty also limits our ability to realistically model future atmospheric CO2 levels. The International SOLAS (Surface Ocean ? Lower Atmosphere Study) science plan and implementation strategy highlights the need for an improved understanding of gas exchange. As stated in the plan ?The objective of [SOLAS] focus 2 is to develop quantitative understanding of processes responsible for air-sea exchange of mass, momentum and energy to permit accurate calculation of regional and global gas and aerosol fluxes. This requires establishing the dependence of these interfacial transfer mechanisms on physical, biological and chemical factors within the atmospheric and oceanic boundary layers...? In this project, researchers at the University of Miami's Rosenstiel School for Marine and Atmospheric Science will make a unique set of measurements of sea-air CO2 exchange measurements in the Southern Ocean as part of the forthcoming ?Southern Ocean Gas Exchange? (SOGasEx) experiment. SOGasEx (also known as GasEx III) is designed to carry out these measurements, and to determine the factors controlling air-sea gas exchange at high winds. The Miami research team expect to enhance the primarily ship-based SOGasex measurements with their unique capabilities to make high resolution measurements of the air-sea interface from autonomous platforms. Specifically they will deploy a new Extreme Air-Sea Interaction (EASI) buoy to measure direct fluxes of CO2, aerosol, sensible and latent heat, and momentum, as well as basic meteorological and oceanic parameters (wind speed, stability, air temperature, humidity, SST, etc), as well as an Air-Sea Interaction Spar (ASIS) buoy to measure the controlling surface physical processes (surface waves including slopes, currents, upper ocean turbulence and mixing). Many of these measurements cannot be made from a ship in a high wave environment due to flow distortion, etc, -- hence the need for autonomous platforms. In addition, they will measure white cap coverage using a camera/video system mounted on the ship. With these measurements, we hope to advance our understanding of gas transfer process related specifically to high wind processes.In terms of broader impacts, this work relates to improvement of our ability to predict atmospheric CO2 levels and to assess how they might change climate under various scenarios. Climate change is emerging as one of the most challenging policy issues faced by governments. Our current lack of an adequate parameterization of air-sea gas transfer rates contributes directly to our inability to predict with certainty future concentrations of CO2 and other climate relevant compounds in the atmosphere. This study is expected to improve the accuracy of global ocean carbon dioxide flux estimates and increase our understanding of the causes of its variability. The proposed measurements employ state-of-the-art instrumentation, which will enhance the SOGasEx experiment. The opportunity to participate in this experiment, and access to the data for subsequent analysis will provide for a unique dataset with which to increase our understanding of the role of air-sea CO2 exchange in influencing climate.