Collaborative Research: Impacts of atmospheric nitrogen deposition on the biogeochemistry of oligotrophic coastal waters

合作研究：大气氮沉降对贫营养沿海水域生物地球化学的影响

• 批准号: 1260574
• 负责人: Raymond Najjar
• 金额: $ 38.61万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-15 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1260574&HistoricalAwards=false
• 关键词: Collaborative; Research; Impacts; atmospheric; nitrogen

Deposition of atmospheric nitrogen provides reactive nitrogen species that influence primary production in nitrogen-limited regions. Although it is generally assumed that these species in precipitation contributes substantially to anthropogenic nitrogen loadings in many coastal marine systems, its biological impact remains poorly understood. Scientists from Pennsylvania State University, William & Mary College, and Old Dominion University will carry out a process-oriented field and modeling effort to test the hypothesis that deposits of wet atmospheric nitrogen (i.e., precipitation) stimulate primary productivity and accumulation of algal biomass in coastal waters following summer storms and this effect exceeds the associated biogeochemical responses to wind-induced mixing and increased stratification caused by surface freshening in oligotrophic coastal waters of the eastern United States. To attain their goal, the researchers would perform a Lagrangian field experiment during the summer months in coastal waters located between Delaware Bay and the coastal Carolinas to determine the response of surface-layer biogeochemistry and biology to precipitation events, which will be identified and intercepted using radar and satellite data. As regards the modeling effort, a 1-D upper ocean mixing model and a 1-D biogeochemical upper-ocean will be calibrated by assimilating the field data obtained a part of the study using the adjoint method. The hypothesis will be tested using sensitivity studies with the calibrated model combined with in-situ data and results from the incubation experiments. Lastly, to provide regional and historical context for the field measurements and the associated 1-D modeling, linked regional atmospheric-oceanic biogeochemical modeling will be conducted.Broader Impacts. Results from the study would be incorporated into class lectures for graduate courses on marine policy and marine biogeochemistry. One graduate student from Pennsylvania State University, one graduate student from the College of William and Mary, and one graduate and one undergraduate student from Old Dominion University would be supported and trained as part of this project.

大气氮的沉积提供了反应性氮种，影响氮限制区域的一级生产。 尽管通常认为这些降水中的这些物种在许多沿海海洋系统中有助于人为氮负荷，但其生物学影响仍然很少。 宾夕法尼亚州立大学，威廉和玛丽学院和旧自治领大学的科学家将进行面向过程的领域和建模努力，以检验以下假设，即湿大气氮的沉积（即降水）刺激了原发性生产力和藻类生物量在夏季暴风雨后的沿海水域和这种作用超过了对风引起的混合的生物地球化学反应，并增加了由美国东部少亲营养的沿海水域的表面新鲜度引起的分层。 为了达到目标，研究人员将在夏季在特拉华湾和沿海卡罗来纳州之间的沿海水域进行拉格朗日野外实验，以确定地表层生物地球化学和生物学对降水事件的反应雷达和卫星数据。 关于建模工作，将通过使用伴随方法吸收一部分研究获得的一部分研究的场数据来校准一个1-D上海混合模型和1D生物地球化学上海洋。 该假设将使用敏感性研究与校准模型结合原位数据和孵育实验结果进行检验。 最后，为了为现场测量和相关的1-D建模提供区域和历史环境，将进行连接的区域大气 - 环境生物地球化学建模。 该研究的结果将纳入有关海洋政策和海洋生物地球化学的研究生课程的课堂讲座中。 一名来自宾夕法尼亚州立大学的研究生，威廉和玛丽学院的一名研究生，以及一名来自旧自治领大学的研究生和一名本科生，将作为该项目的一部分得到支持和培训。