Characterizing a refractory DOC sink in the deep northern North Pacific

海洋中的难降解溶解有机碳（RDOC）长期以来被认为是高度耐去除的。 它在海洋中的平均寿命为数千年，因此通常被认为是一个主要通过温盐环流保守输送的淡水池。 但与现今海洋中的RDOC不同，古海洋学研究表明，这个巨大的水库是过去气候变化中相对快速周转的碳源/汇。 因此，古代海洋中的RDOC储存库有时一定比今天大得多，而且这个大的储存库一定被迅速动员起来，将其碳释放到大气中。 显然需要了解RDOC源和汇过程如何在现代海洋中运作，以便了解其在过去或未来海洋中的潜在作用。在该项目中，大学罗森斯蒂尔海洋与大气科学学院的研究人员希望填补RDOC与气候联系方面的知识空白。迈阿密。 由于其全球分布的绘图仅在过去几年中完成，因此关于控制RDOC池的过程的可靠事实很少。 北太平洋北方是一个特别重要的RDOC汇。 PI认为，从南大洋到遥远北方的底层沃茨中携带的RDOC是保守的，但一旦进入太平洋深水地层附近，碳就会突然流失。 他在这个项目中的近期目标是描述北太平洋的RDOC汇，这是理解海洋RDOC在全球气候中的作用这一更大目标的一部分。更广泛的影响：现代海洋碳循环的拟议研究将为我们提供海洋DOC在地球过去和未来气候中的作用的新见解。 这项研究的主题也与首席研究员目前在帮助实施新的美国碳循环科学计划方面的领导责任密切相关。

Refractory dissolved organic carbon (RDOC) in the ocean has long been recognized as highly resistant to removal. It has a mean lifetime in the ocean of thousands of years, so it is generally thought of as a recalcitrant pool that is transported mostly conservatively with the thermohaline circulation. But unlike RDOC in the present-day ocean, this vast reservoir has been implicated by paleoceanographic research as a relatively rapid-turnover carbon source/sink involved in past climate changes. Accordingly, the RDOC reservoir in ancient oceans must at times have been much larger than today, and that large reservoir must have been rapidly mobilized to release its carbon to the atmosphere. There is a clear need to understand how RDOC source and sink processes operate in the modern ocean in order to understand its potential role in past or future oceans.In this project, a researcher at the Rosenstiel School of Marine and Atmospheric Science of the University of Miami hopes to fill knowledge gaps in the RDOC-climate connection. Inasmuch as mapping of its global distribution was accomplished only within the past few years, few solid facts about processes controlling the RDOC pool have been established. One particularly important RDOC sink is in the northern North Pacific. The PI believes that RDOC carried in bottom waters from the Southern Ocean to the far north is conserved, but once in the vicinity of Pacific Deep Water formation there is a rather abrupt loss of carbon. His immediate goal in this project is to characterize the RDOC sink in the North Pacific, an objective that is one part of the larger goal of understanding the role of ocean RDOC in global climate.Broader Impacts: The proposed studies of the modern ocean carbon cycle will give us new insights on the role of marine DOC in Earth's past and future climates. The topic of this research is also closely related to the principal investigator's current leadership responsibilities in helping to implement the new U.S. Carbon Cycle Science Plan.