Nitrate-Ammonium Interactions And Nitrate Supply In The Regulation Of Arabian Sea Regional New Production.

阿拉伯海区域新生产调节中的硝酸盐-铵相互作用和硝酸盐供应。

• 批准号: 9310629
• 负责人: James McCarthy
• 金额: $ 49万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-15 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9310629&HistoricalAwards=false
• 关键词: Nitrate; Ammonium; Interactions; Supply; Regulation; Nitrate; Ammonium; Interactions; Supply; Regulation

McCarthy 9310629 Quantitative elcucidation of the processes that regulate biological production in the sea is fundamental to an understanding of the role the oceans play in the earth's climate system. Temporal and spatial variability in the processes that govern the upward rate of nutrient flux from the deep-sea, and the drift of currents in the upper ocean, determine the distribution of marine plankton and set limits for their production. Pursuit of JGOFS objectives requires investigation into these physical-biological linkages. They influence the global rates of carbon sequestration and release by the sea. How balance between these processes was regulated in the past, and how it is regulated today is an important research component of US national and international endeavors to understand and predict responses to global change. The monsoonal system of the Arabian Sea affords unique opportunity for the pursuit of these studies. Its intense seasonal cycle in air-sea interaction allows for the development and testing of models relating to the physical climate-driven process linkages to biological responses and consequent feedback via air-sea exchange of gases. In addition to the intensity of these processes, and hence their strong seasonal signal in the Arabian Sea, the record of the past, recorded in marine fossil assemblages and isotopes in ocean sediments, is valuable in the development and testing of time varying models treating coupled physical and biological aspects of the ocean climate system. This study relates to one particular link in the system: the regulation of primary planktonic production by the supply rate of the limiting nutrient, nitrogen. The coarse seasonal pattern in Arabian Sea production is one of the most intense, production being associated with the summer SW monsoon. Upwelling delivers a pulse of nutrients to surface waters, which in turn stimulates a plankton bloom in the northern Arabian Sea. During the balance of the year, production rates are lower, but remain generally higher than those typical of oceanic waters elsewhere. In this study the availability of nitrogen, both in the upwelled form of nitrate and in the recycled form of ammonium, will be assessed regionally during the low production NE winter monsoon and the two inter-monsoon transition periods. The interplay between dependence on the "new" and "regenerated" forms of nitrogen determine what fraction of total primary production is at any time available for export to the deep- sea. The techniques applied will permit the quantification of new production and its regulation throughout the low nutrient portion of the year. Nutrient analyses sensitive in the nanomolar range will be employed for quantifying the abundance, and with 15N labeled substrates, the rates of supply and utilization of nitrite, nitrate and ammonium in the upper ocean. This study will be conducted in collaboration with investigators who are addressing other aspects of the nitrogen cycle and biological production. New understanding resulting from these complementary projects will contribute to the formulation and testing of regional models that use remotely sensed information on biological and physical features and processes to better predict how production processes in the Arabian Sea will respond to future climate change. ***

麦卡锡（McCarthy）9310629对调节海中生物生产的过程的定量性促进是对海洋在地球气候系统中扮演的作用的基础。 在控制深海营养通量上升速率的过程中的时间和空间变异性，以及上海流的电流漂移，决定了海洋浮游生物的分布并为其生产设定限制。 追求JGOF目标需要调查这些物理生物学联系。 它们会影响碳固存的全球速度和海洋释放。 这些过程之间的平衡是如何受到过去的调节，以及今天的规范是美国国家和国际努力的重要研究组成部分，以理解和预测对全球变化的反应。 阿拉伯海的季风系统为追求这些研究提供了独特的机会。 它在空气相互作用中的强烈季节性周期允许开发和测试与物理气候驱动的过程与生物学反应的链接相关的模型，并通过气体交换气体交换而随之而来的反馈。 除了这些过程的强度以及它们在阿拉伯海中的强烈季节性信号外，过去记录在海洋沉积物中的海洋化石组合和同位素中记录的记录，对于时间变化和测试的模型，在海洋气候系统的物理和生物学方面进行了变化。 这项研究涉及系统中的一个特定联系：通过限制营养素氮的供应率调节原发性浮游生物的产生。 阿拉伯海生产中的粗糙季节性模式是最激烈的生产之一，与夏季SW季风有关。 上升的养分为地表水带来了一大堆营养，这反过来刺激了阿拉伯海北部的浮游生物。 在一年的余额中，生产率较低，但总体上仍然高于其他地方的海洋水域。 在这项研究中，将在低生产NE冬季季风和两个季风间过渡期间进行区域评估氮的可用性，无论是硝酸盐的上流形式还是以铵的再生形式进行评估。 对氮的“新”和“再生”形式的依赖之间的相互作用决定了任何时间可用于导出到深海的总生产的哪一部分。 所应用的技术将允许在一年中整个养分部分中定量新生产及其调节。 纳莫尔范围内的营养分析敏感，用于量化丰度，并具有15N标记的底物，上海的亚硝酸盐，硝酸盐和氨的供应速率和利用率。 这项研究将与正在解决氮周期和生物生产的其他方面的研究人员合作进行。 这些互补项目产生的新理解将有助于对区域模型的制定和测试，这些模型使用有关生物学和物理特征和过程的远程感知的信息，以更好地预测阿拉伯海中的生产过程将如何应对未来的气候变化。 ***