Primary Production Rates in the N. Atlantic for O2 Isotopes and O2/Ar

由于越来越多的证据表明，海洋的生物泵随着自然气候的变化而变化，海洋学家在未来十年的一项主要任务是区分海洋生物泵强度的自然变化和人为变化。尽管海洋具有全球重要性，但它的生物泵率并不是真正众所周知的。初级生产力在短时间和空间尺度上的变异性使得使用传统的基于14C的方法难以准确地测量生产率。显然需要使用更准确、应用时间更短、可以在更长的时间/空间尺度上整合的替代初级生产率测量方法。在这项研究中，华盛顿大学的一位科学家将在详细的空间和时间尺度上确定北大西洋亚北极地区初级生产总值和社区净生产率的年度周期。他将对北大西洋反复集装箱船横渡大西洋时采集的表层海水样本进行几乎每月(3年内约50个月)的溶解氧气体三重同位素组成(17‘)和溶解氧与Ar气体比率(O2/Ar)的测量，经度分辨率为1’。这些样本收集将作为CARBOCEAN计划的一部分，通过与基尔大学的研究人员合作进行。此外，他还将与美国国家科学基金会资助的另一支探险队合作，于2008年春季在亚北极的北大西洋测量同样的速率，在那里，浮标、海滑器和卫星将被用来研究春季水华期间对中尺度物理强迫(例如锋面、风暴、涡流)的生物反应。这套测量将能够确定整个北大西洋次北极的初级生产总值和净群落生产的年度周期，澄清净群落生产的时空变化对表层二氧化碳水平和海气二氧化碳净吸收的影响，并审查初级生产力的中尺度变异性与北大西洋春季水华期间的物理强迫之间的关系。这项拟议研究的更广泛影响包括帮助改进对大气二氧化碳增加导致未来全球变暖的预测。这项拟议的工作涉及与欧洲海洋学社区的大量合作，并将支持一名本科生进行这项研究。

Because of the mounting evidence that the ocean's biological pump changes with natural climate shifts, a major task of oceanographers over the coming decade is to separate natural from anthropogenic shifts in the strength of the ocean's biological pump. Despite its global importance, the ocean's biological pump rate is not really well known. Variability of primary production rates on short time and space scales makes difficult the accurate measurement of rates using traditional 14C-based methods. There is a clear need to use alternative primary production rate measurement methods that are more accurate, less time consuming to apply and can integrate over longer time/space scales. In this research, a scientist from the University of Washington will determine, on a detailed spatial and temporal scale, the annual cycle of gross primary production and net community production rates across the subarctic N. Atlantic Ocean. He will make almost monthly measurements (~50/month over 3 years) of both the triple isotopic composition of dissolved oxygen gas (17') and the dissolved oxygen and argon gas ratio (O2/Ar) on surface seawater samples collected during repeated container ship crossings of the N. Atlantic with ~1' of longitude resolution across the basin. These sample collections will be made as part of the CARBOOCEAN program through a collaboration with researchers at U. Kiel. Additionally, in collaboration with another NSF-funded expedition, he will measure the same rates in the subarctic N. Atlantic in Spring 2008 where floats, seagliders and satellites will be used to examine the biological response during the spring bloom to mesoscale physical forcing (e.g. fronts, storms, eddies). This suite of measurements will permit determination of the annual cycle of gross primary production and net community production across the subarctic N. Atlantic Ocean, clarify the impact that spatial and temporal variations of net community production have on surface pCO2 levels and net air-sea CO2 uptake, and examine the relationship between mesoscale variability in primary production rates and physical forcing during the spring bloom in the N. Atlantic. The broader impacts of the proposed research include helping to improve predictions of future global warming due to atmospheric CO2 increases. The proposed work involves a substantial collaboration with the European oceanographic community and will support an undergraduate student in the research.