POWRE: An Arctic Ocean Time-Series of Dissolved Inorganic Carbon

POWRE：北冰洋溶解无机碳的时间序列这一研究项目的目标是评估北冰洋中部生物生产和呼吸的季节模式，重点是预测海-气碳交换的方向和程度。这项研究将补充波弗特海东部边缘常年冰盖中建立的一个为期一年的野外空间站(SHEBA)的资助研究。海洋学家将首次使用现代方法观测北极中部海洋碳循环的几乎所有主要组成部分，全年至少每周一次。资助的原则调查人员，惠勒等人。韦尔奇等人将测量溶解氧和营养物、颗粒和溶解有机碳、自养和异养生物量(从微浮游生物到北极熊)，以及初级和次级生产和呼吸速率。这些测量将在更大的表面热量收支实验(NSF-SHEBA、DOE-ARM、NASA-FIRE、ONR-HLP)的背景下进行，其中将全年监测许多与生物地球化学相关的物理参数。两个关键参数--总溶解无机碳(CT)和碱度(AT)--是完成碳收支和将北冰洋生态系统与全球碳循环联系起来所必需的，但供资计划至今没有这两个参数。这项提议旨在弥补这些缺失的环节。我建议使用北极表层水域CT和AT的每周深度剖面来检测溶解无机(DIC)和有机碳(OC)池之间的碳的生物转化，特别是光学期净初级生产力的程度，黑暗冬季的呼吸速率，以及春季冰藻对近地表DIC浓度的影响。通过测量CT和AT，我们可以计算估计气体交换所需的二氧化碳分压，还可以使用碱度作为河流、海冰和其他水团贡献的示踪剂。虽然常年被冰覆盖的海洋历来被认为是“净异养”生态系统，但这些估计通常依赖于夏季的测量。利用一个覆盖整个年度周期的数据集，我们(我和我的合作者)建议检验以下假设：1)自养超过异养，2)自养和异养之间存在季节补偿，3)冬季异养是由春季和初夏当地产生的DOC支持的，以及4)本地生产和呼吸平衡。通过提供生物过程和二氧化碳之间的联系，我的数据将使我们能够进一步测试这片常年被冰覆盖的北冰洋地区(净异养、净自养或平衡)是大气二氧化碳的来源还是汇。POWRE奖将对亚格博士的职业生涯产生重大影响。作为一名新的研究人员，这一奖项将提供一个机会，通过获得最先进的海洋野外设备和与国际知名的海洋学家团队合作来加强她的研究活动。

POWRE: An Arctic Ocean time-series of dissolved inorganic carbon The goal of this research project is to evaluate seasonal patterns of biological production and respiration in the central Arctic Ocean with an emphasis on predicting the direction and extent of air-sea carbon exchange. This research would complement funded research at a year-long field-station (SHEBA) established in the perennial ice pack along the eastern edge of the Beaufort Sea. For the first time ever with modern methods, oceanographers will observe nearly all major components of the central Arctic marine carbon cycle with at least weekly resolution over an entire year. Funded Principle Investigators, Wheeler et al. and Welch et al., will measure dissolved oxygen and nutrients, particulate and dissolved organic carbon, autotrophic and heterotrophic biomass (ranging from picoplankton to polar bears), and primary and secondary production and respiration rates. These measurements will be made in the context of a larger surface heat budget experiment (NSF-SHEBA, DOE-ARM, NASA-FIRE, ONR-HLP) where many biogeochemically-relevant physical parameters will be monitored throughout the year. Two key parameters, total dissolved inorganic carbon (CT) and alkalinity (AT), needed to complete the carbon budget and link the Arctic Ocean ecosystem to the global carbon cycle, are as yet missing from the funded plan. This proposal is designed to provide these missing links. I propose to use weekly depth profiles of CT and AT in Arctic surface waters to detect the biological transformations of carbon between the dissolved inorganic (DIC) and organic carbon (OC) pools, specifically the extent of net primary production during the photic period, respiration rates during the dark wintertime, and the effect of springtime ice algae on near-surface DIC concentration. By measuring both CT and AT, we can calculate pCO2, needed to estimate gas exchange, and also use alkalinity as a tracer for contributions from rivers, sea-ice, and other water masses. While perennially ice-covered seas have been historically considered `net heterotrophic` ecosystems, these estimates have typically relied on summertime measurements. With a data set covering an entire annual cycle, we (myself and my collaborators) propose to test the following hypotheses: that 1) autotrophy exceeds heterotrophy during parts of the year, 2) a seasonal offset exists between autotrophic and heterotrophic production, 3) wintertime heterotrophy is supported by DOC produced locally during the spring and early summer, and 4) local production and respiration balance on an annual basis. By providing the link between biological processes and pCO2, my data would allow us to test additionally whether this region of perennially-ice covered Arctic seas (net heterotrophic, net autotrophic, or balanced) is, on an annual basis, a source or sink for atmospheric CO2. The POWRE award would have a significant impact on the career of Dr. Yager. As a new investigator, this award will provide an opportunity to enhance her research activities through access to state-of-the-art oceanographic field equipment and the opportunity to collaborate with an internationally known team of oceanographers.