Measurements of Air-Sea Gas Transfer and Bubble Dynamics in the Southern Ocean during a SOLAS Dual Tracer Experiment

在这个项目中，哥伦比亚大学拉蒙特-道格拉斯地球观测站（LDEO）的研究人员将参与由新西兰科学小组领导的国际SOLAS（表层海洋低层大气研究）双重示踪气体交换研究。该研究旨在提高我们对南大洋气体交换及其对风速和其他因素的依赖性的理解，南大洋是大气CO2海气交换的关键区域。 气体传输速度（k）与风速的参数化并不理想，因为还有其他因素影响k。 然而，许多研究人员依赖这些参数化来推导气体传输速度，因此继续改进k与风速（或均方波斜率）关系的参数化对于提高对全球地球化学收支（包括CO2）的理解至关重要。 300次测量）的双示踪剂实验（3 He/SF6），将提供空间和时间平均的k在一段时间内约。 20天和一个地区。250平方公里。在46.67 'S，178.5 'E，将~ 3 He和SF_6的混合物注入到混合层中，对所形成的示踪斑进行了约1000 m的观测。20天k可以从靠近斑片中心的3 He/SF6比率的降低速率导出。 根据实验过程中的风况，研究小组应该能够在风速范围内获得4到8个k的估计值。2和14 m s-1。 这些数据将被用来测试如何以及气体交换参数化，来自全球海洋14 C库存和支持的双重示踪气体交换实验在沿海和大陆架地区进行的结果，可以外推到较高的南部纬度。双示踪剂的结果将补充短时间尺度，小空间尺度的测量k的基础上微气象测量（涡相关的CO2，和放松涡积累测量CO2和DMS）。 除了双示踪剂测量外，该团队还将进行Ne，N2，O2和Ar测量（与罗得岛大学和普林斯顿大学的同事合作），以更好地了解高风速下气泡在气体交换中的作用。 总之，这些数据应改善我们的知识k在南大洋的数据稀疏的区域，并显着有助于缩小我们的知识的一个关键差距的海气通量，从而解决SOLAS科学计划的一个关键要素。

ABSTRACTOCE-0327779In this project, researchers at the Lamont-Dougherty Earth Observatory (LDEO) of Columbia University will participate in an international SOLAS (Surface Ocean Lower Atmosphere Study) dual tracer gas exchange study led by a New Zealand scientific team. The study aims at improving our understanding of gas exchange and their dependence on wind speed and other factors in the Southern Ocean, a key region for air-sea exchange of atmospheric CO2. Parameterization of gas transfer velocity (k) with wind speed is not ideal, as there are other factors that contribute to influence k. However, many investigators rely on these parameterizations to derive gas transfer velocities so continuing to improve the parameterization of k versus wind speed (or mean square wave slope) relationships is critical for improving understanding of global biogeochemical budgets, including that of CO2.During the experiment, the LDEO team will contribute the 3He data (ca. 300 measurements) to a dual tracer experiment (3He/SF6) that will provide spatially and temporally averaged k over a period of ca. 20 days and a region of ca. 250 km2. For this experiment, a mixture of 3He and SF6 will be injected into the surface mixed layer at 46.67 'S, 178.5 'E, and the resulting tracer patch will be surveyed for ca. 20 days. k can be derived from the rate of decrease in the 3He/SF6 ratio close to the center of the patch. Depending on the wind regime during the experiment, the team should be able to obtain 4 to 8 estimates of k over a range of wind speeds between ca. 2 and 14 m s-1. These data will be used to test how well gas exchange parameterizations, derived from global ocean 14C inventories and supported by results from dual tracer gas exchange experiments conducted in coastal and shelf area, can be extrapolated to higher southern latitudes. The dual tracer results will be complemented by short time scale, small spatial scale measurements of k that are based on micrometeorological measurements (eddy correlation of CO2, and relaxed eddy accumulation measurements of CO2 and DMS). In addition to the dual tracer measurements, the team will perform Ne, N2, O2 and Ar measurements (in collaboration with colleagues at the University of Rhode Island and Princeton University) to understand better the role of bubbles in gas exchange at high wind speeds. Taken together, these data should improve our knowledge of k in the data-sparse regions in the Southern Ocean and significantly contribute to closing a critical gap in our knowledge of air-sea gas fluxes, thereby addressing a key element of the SOLAS science plan.