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

测试 N2/Ar 比率以测量大陆架沉积反硝化作用

• 批准号: 9617960
• 负责人: John Christensen
• 金额: $ 24.77万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-02-15 至 2002-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9617960&HistoricalAwards=false
• 关键词: Testing; N2; Ar; Ratios; Measuring

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)

摘要大陆架沉积物中的OCE-9617960反硝化速率具有全球意义，因为它们影响海洋表层水中营养物质的有效性，调节海洋生产力，并影响大气二氧化碳浓度。确定这些速率的经典方法是有限的，因为不能准确地估计沿海海洋中或低速率的大范围区域的氮通量，而且这些区域可能比那些已经确定的高速率区域在全球范围内更重要。这项建议的目的是扩大我们在低或中等氮通量地区测量反硝化率的能力。首席调查员将采用的办法是使用更精确的质谱学技术，不仅测量氮，而且测量氮/氩比，以便更准确地确定从缅因湾地区试验场收集的沉积物岩心中的氮通量。首席研究员是全球氮循环研究的领先先驱，基于这一新方法的进展将极大地扩展我们识别和量化全球海洋系统氮源和汇的能力。克里斯滕森(OCE-9617960)