Collaborative Research: Understanding the Changing Global Distribution of Radiocarbon: Sampling and Analysis from GO-SHIP and Ships of Opportunity Cruises

放射性碳一直被认为是海洋过程研究的重要示踪剂。该项目的主要目标是继续对海洋放射性碳分布进行系统的全球重新采样，作为美国全球海洋碳和重复水文计划的一部分，该计划是国际全球海洋船舶水文调查计划（GO-SHIP）持续观测网络的一部分。对选定的重复水文线的持续采样以及从其他重要区域收集的样本将为全球碳循环界提供一个强大的数据库来测试海洋环流模型。这一点尤其重要，因为我们依赖这些模型来预测全球二氧化碳增加的后果。本研究产生的数据可用于研究混合、通风率、生产速率、在深海的停留时间、深海生物地球化学和氧气利用率、海气交换、温跃层通风率，作为海洋中人为二氧化碳的代理，并评估海洋环流模型的性能。收集的样本主要集中在但不限于印度洋和南大洋。研究人员将在未来5年内收集和分析计划重复的大西洋水文学巡航的样本。除了监测核弹- 14c瞬态变化外，整个计划的采样将有助于提供印度洋三维放射性碳分布的最新估计。按照设计，他们的重复采样计划比一般的重复水文计划要慢一些。这一削减是基于预算考虑、样品分析能力和巡航计划的妥协。他们还将在南大洋取样，作为南大洋碳和气候观测与建模（SOCCOM）工作的一部分。这些样品将记录放射性碳在这个知之甚少的海洋区域的分布，并提供有关碳通量和通过该地区运输的重要信息。

Radiocarbon has long been recognized as an important tracer for studies of ocean processes. The major objective of this project is to continue a systematic global resampling of the oceanic radiocarbon distribution as part of the US Global Ocean Carbon and Repeat Hydrography program, a part of the international Global Ocean Ship-Based Hydrographic Investigations Program (GO-SHIP) network of sustained observations. Continued sampling of select repeat hydrography lines as well as the collection of samples from other important regions will provide the global carbon cycle community with a robust database to test ocean general circulation models. This is particularly important based on our reliance on such models to predict the consequences of increased global carbon dioxide. Data generated from this study can be used to study mixing, ventilation rates, production rates, residence times in the deep ocean, deep ocean biogeochemistry and oxygen use rates, air-sea gas exchange, thermocline ventilation rates, as a proxy for anthropogenic carbon dioxide in the ocean, and to evaluate ocean general circulation model performance. The samples to be collected are focused on, but not limited to, the Indian and the Southern Oceans. The researchers will collect and analyze samples from planned repeat hydrography Atlantic cruises over the next 5 years. The total planned sampling will help provide an updated estimate of the three dimensional radiocarbon distribution for the Indian Ocean in addition to monitoring changes in the bomb-14C transient. Their repeat sampling schedule is, by design, a bit slower than for the general Repeat Hydrography program. This reduction is a compromise based on budgetary considerations, sample analysis capacity and cruise plans. They will also sample in the Southern Ocean as part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) effort. These samples will document the radiocarbon distribution in this poorly understood region of the ocean and provide important information about carbon flux and transport through this area.