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生物泵随着自然气候变化而变化，海洋学家在未来十年的一项主要任务是将海洋生物泵强度的自然变化与人为变化区分开来。尽管海洋的生物泵率在全球具有重要意义，但人们并不真正了解海洋的生物泵率。初级生产速率在短时间和空间尺度上的变异性使得使用传统的基于14c的方法精确测量速率变得困难。显然，需要使用替代的初级生产率测量方法，这些方法更准确，使用时间更短，并且可以在更长的时间/空间尺度上进行整合。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整个亚北极北大西洋的总初级生产力和净群落生产力的年周期。他将几乎每月（3年内每月~50次）测量溶解氧（17′）的三同位素组成和溶解氧与氩气的比值（O2/Ar），这些样品是在集装箱船以~1′的经度分辨率穿越盆地，反复穿越北大西洋时收集的。通过与基尔大学的研究人员合作，这些样品收集将作为CARBOOCEAN计划的一部分。此外，在与另一个由nsf资助的考察队的合作下，他将于2008年春季在北大西洋亚北极地区测量相同的速率，届时将使用浮子、滑翔机和卫星来检查春季水华对中尺度物理强迫（如锋面、风暴、漩涡）的生物反应。这套测量方法将确定北大西洋亚北极地区总初级生产量和净群落生产量的年循环，阐明净群落生产量的时空变化对表层二氧化碳分压水平和海气二氧化碳净吸收的影响，并研究北大西洋春季水华期间初级生产量中尺度变率与物理强迫之间的关系。拟议研究的更广泛影响包括帮助改进对未来大气二氧化碳增加导致的全球变暖的预测。拟议的工作涉及与欧洲海洋学社区的实质性合作，并将支持一名本科生进行研究。

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.