Collaborative Reserach: Mechanisms Controlling Upper Ocean Carbon Fluxes in the North Pacific

每年进入太平洋北纬14度以北海洋的二氧化碳通量与赤道太平洋（北纬14度至14度）每年进入大气的二氧化碳通量大致相等。北太平洋二氧化碳吸收最强的区域是亚热带亚北极锋。虽然热力学过程主要控制着亚热带的海气CO2通量，但生物和物理机制在锋面和亚北极太平洋更为重要。根据目前的了解，尚不确定为应对气候变化而改变这些物理和生物过程是否会将北太平洋转变为一个更强的二氧化碳源，甚至变成一个人为二氧化碳汇。在这项研究中，来自华盛顿大学和俄勒冈州立大学的专业人员将与美国国家海洋和大气管理局太平洋海洋生态系统实验室的科学家密切合作，结合卫星观测和模拟调查进行实地研究，以确定亚热带亚北极锋和亚北极太平洋东部盆地的海气二氧化碳通量控制机制。实地研究包括三个独立的组成部分：(1)利用每隔一个月穿越太平洋的志愿观测船（VOS）测量二氧化碳分压和生物生产力的氧同位素示踪剂（delta17O, O2/Ar）；(2)利用夏威夷和西雅图之间的研究巡航，确定无法从VOS获得的碳通量和深度分布；(3)在亚北极太平洋东部海洋站P的表层系泊上连续测量T、S、O2、叶绿素、pCO2和pH，同时使用滑翔机对该地区进行测量T、S和O2的四维分布。这些自主测量的重点是确定间歇性在生物泵中的作用。实地观测将与一项卫星产品研究结合起来，该研究确定了间歇性强迫（例如海面高度、大气尘埃水平）和随后的生产力事件（例如海洋颜色、球石藻华）的作用。包括生物生态系统和碳酸盐化学模块在内的北太平洋环流模式将与实地和卫星数据相结合，以帮助区分控制锋面区地表水二氧化碳分压的物理和生物过程的重要性。最明显的更广泛的影响是，作为华盛顿大学海洋学学生课程的一部分，10 - 15名本科生和研究生参加了夏威夷和西雅图之间的研究考察。这项研究还将支持两名半研究生，他们将使用这里获得的数据来完成他们的博士研究。在这一至关重要的制度中，对碳循环的更深入了解将带来社会效益。

The annual CO2 flux into the ocean north of 14 degN in the Pacific is about equal to the annual flux to the atmosphere from the Equatorial Pacific (14 degN to 14 degS). The strongest region of CO2 uptake in the north Pacific is at the subtropical subarctic front. Although thermodynamic processes primarily control the air-sea CO2 flux in the subtropics, biological and physical mechanisms are much more important at the front and in the subarctic Pacific. Based on current understanding, it is uncertain whether alterations to these physical and biological processes in response to climate change could transform the north Pacific into a stronger source or even into a sink for anthropogenic CO2. In this research, PIs from the University of Washington and Oregon State University, in close collaboration with scientists from NOAA's Pacific Marine Ecosystems Laboratory, will conduct field studies combined with satellite observations and a modeling investigation to identify the mechanisms controlling the air-sea CO2 flux at the subtropical subarctic front and in the eastern basin of the subarctic Pacific. The field studies comprise three separate components: (1) measurement of pCO2 and oxygen isotope tracers of biological productivity (delta17O, O2/Ar) using a Volunteer Observation Ship (VOS) that crosses the Pacific every other month; (2) determination of carbon fluxes and depth distributions not possible from a VOS using a research cruise between Hawaii and Seattle, and (3) in situ, continuous measurement of T, S, O2, chlorophyll, pCO2 and pH on a surface mooring in the eastern subarctic Pacific at Ocean Station P while simultaneously measuring the four dimensional distribution of T, S, and O2 using a Seaglider survey of the area. These autonomous measurements are focused on identifying the role of intermittency in the biological pump. The field observations will be placed in context by a study of satellite products that identify the role of intermittent forcing (e.g. sea-surface height, atmospheric dust levels) and subsequent productivity events (e.g. ocean color, coccolithophorid blooms). A circulation model of the north Pacific that includes modules for the biological ecosystem and the carbonate chemistry will be combined with the field and satellite data to help distinguish the importance of physical and biological processes in controlling the pCO2 of surface waters at the frontal region. The most obvious broader impact is the participation of 10 - 15 undergraduate and graduate students on a research expedition between Hawaii and Seattle as part of a course for students of Oceanography at the University of Washington. This research will also support two and one half graduate students who will use the data derived here to complete their Ph.D. research. A greater understanding of carbon cycling in this critically important regime will provide societal benefits.