Testing N2/Ar Ratios for Measuring Sedimentary Denitrification in Continental Shelves

摘要 OCE-9617960 大陆架沉积物中的反硝化作用具有全球意义，因为它们影响到海洋表层沃茨中的营养物质，调节海洋生产力，并影响大气中的二氧化碳浓度。 传统的方法来确定这些率是有限的，因为氮通量不能准确地估计从广泛的沿海地区的速度是中等或低，这些地区可能是更重要的全球比那些地区已经确定与高利率。 这项建议的目的是扩大我们的能力，在低或中等氮通量的地区测量反硝化速率。 主要研究员采用的方法是使用更精确的质谱技术，不仅测量氮，而且测量氮/氩比，以便更准确地确定从缅因州海湾地区试验点收集的沉积物芯中的氮通量。 首席研究员是全球氮循环研究的领先先驱，基于这种新方法的进展应该大大扩展我们识别和量化海洋系统中氮的全球来源和汇的能力。 Christensen（OCE-9617960）

ABSTRACT OCE-9617960 Denitrification rates in continental shelf sediments are globally significant in that they affect nutrient availability in surface waters of the ocean, modulate oceanic productivity and influence atmospheric carbon dioxide concentrations. Classical approaches to determine these rates are limited, since nitrogen fluxes cannot be accurately estimated from wide areas of the coastal ocean where rates are moderate or low, and these regions may be more important globally than those areas already identified with high rates. The objective of this proposal is to expand our ability to measure denitrification rates in areas of low or moderate nitrogen fluxes. The approach to be employed by the principal investigator is to use a more precise mass spectrometric technique, where not only nitrogen, but nitrogen/argon ratios are measured in order to determine more accurately nitrogen fluxes in sediment cores collected from test sites in the Gulf of Maine region. The principal investigator is a leading pioneer in studies of the global nitrogen cycle, and advances based upon this new method should expand significantly our ability to identify and quantify global sources and sinks of nitrogen in marine systems. Christensen (OCE-9617960)