Nitrogen Gas Measurement Facility at the Cary Institute of Ecosystem Studies

了解景观、区域和全球尺度的氮循环是环境科学中的一个巨大挑战。 人类每年生产的“活性”氮增加了一倍以上，导致许多地区的空气和水质以及沿海生态系统恶化。 氮循环中最不确定的组成部分是陆地和水生生态系统中氮气、一氧化氮（NO）、一氧化二氮（N2O）和二氮（N2）的通量。 这些气体受到多种生物、化学和物理因素的影响，其通量通常变化很大且难以量化。 应对氮气的挑战需要三个关键组成部分； 1) 测量氮循环中涉及的所有三种气体（NO、N2O、N2），2) 量化环境关键成分内部和之间的气体通量；土壤、水（包括土壤水、地下水、溪流、河流等）和大气；3）流域/质量平衡背景下的通量评估。所有这些组件都可以通过在现场和实验室中协调部署的一套集成仪器来解决，并结合其他测量。卡里研究所在哈伯德布鲁克和巴尔的摩长期生态 (LTER) 研究中心领导氮气研究。在这些地点，对氮输入和水文输出的长期监测为开发和测试有关气体通量的重要性和控制因素的假设提供了强大的平台。这些资金购买的仪器将用于改善和扩大这两个 LTER 站点的长期氮气监测。另一个主要关注点是卡里研究所，该研究所拥有长期环境监测计划，是比较和评估测量氮气通量的新方法的理想试验台。近 20 年来，卡里研究所一直是氮气研究和培训的中心。 来自多个机构的众多本科生（REU）参与者、研究生和博士后研究人员在我们的实验室进行了氮气研究。这种新仪器将使该研究所能够继续在这一关键但高度专业化的研究领域发挥重要的教育和网络作用。该项目将建立卡里研究所氮气测量设施，该设施将由一套集成仪器组成，可在生态系统、景观和区域规模评估所必需的质量平衡背景下，对多种介质（土壤、水、大气）中的多种气体（N2、N2O、NO）进行量化。该套件的关键组件包括直接测量从土壤和沉积物岩心到大气的气体通量（包括氮气）的仪器、用于在现场室和涡流方法中量化从土壤到大气的原位气体通量的传感器，以及用于量化水中溶解的氮气的膜入口质谱仪。哈伯德布鲁克和巴尔的摩 LTER 站点正在进行的长期研究以及卡里研究所的长期环境监测计划迫切需要使用和维护仪器。卡里研究所氮气主要测量设施将在 Peter Groffman 博士的监督下建立。格罗夫曼实验室现任首席研究支持专家在氮气通量的现场和实验室测量方面拥有 10 多年的经验，并培训了众多本科生、研究生和博士后研究人员。 卡里研究所的高级研究支持专家在空间分配、新用户培训以及仪器维护和故障排除方面积极合作。 大部分合作由研究所支持的实验室设施和分析服务总监、安全官员和卡里研究所环境监测项目经理管理。有关凯里研究所的更多信息，请访问 http://www.caryinstitute.org/。

Understanding the nitrogen cycle at landscape, regional and global scales is a great challenge in environmental science. Humans have more than doubled the annual global production of "reactive" nitrogen, leading to degradation of air and water quality and coastal ecosystems in many areas. The most uncertain component of the nitrogen cycle is the flux of nitrogen gases, nitric oxide (NO), nitrous oxide (N2O) and dinitrogen (N2) in terrestrial and aquatic ecosystems. These gases are affected by multiple biological, chemical and physical factors and the fluxes are often highly variables and difficult to quantify. Addressing the challenge of nitrogen gases requires three key components; 1) measurement of all three gases (NO, N2O, N2) involved in the nitrogen cycle, 2) quantification of gas fluxes in and between key components of the environment; soil, water (including soil water, groundwater, streams, rivers, etc) and atmosphere and 3) evaluation of fluxes in a watershed/mass balance context. All of these components can be addressed with an integrated suite of instruments deployed in the field and laboratory in a coordinated manor, in context with other measurements. The Cary Institute leads nitrogen gas research at the Hubbard Brook and Baltimore Long Term Ecological (LTER) research sites. At these sites, long-term monitoring of nitrogen inputs and hydrologic outputs provide a strong platform for developing and testing hypotheses about the importance and controlling factors of gas fluxes. The instruments purchased with these funds will be used to improve and expand the long-term nitrogen gas monitoring at these two LTER sites. An additional major focus would be at the Cary Institute, which has a long-term environmental monitoring program and is an ideal testbed for comparison and evaluation of new approaches to measuring nitrogen gas fluxes. The Cary Institute has served as a nexus for nitrogen gas research and training for nearly 20 years. Numerous Research Experiences for Undergraduates (REU) participants, graduate students and postdoctoral researchers from multiple institutions have conducted nitrogen gas studies in our laboratory. This new instrumentation will allow the institute to continue to play an important educational and network role in this critical, but highly specialized area of research.This project will establish the Cary Institute Nitrogen Gas Measurement Facility which will consist of an integrated suite of instruments that will allow for quantification of multiple gases (N2, N2O, NO), in multiple media (soil, water, atmosphere), in the mass balance context that is necessary for ecosystem, landscape and regional scale assessments. Key components of this suite include instruments to directly measure gas fluxes (including N2) from soil and sediment cores to the atmosphere, sensors for quantifying in situ fluxes of gases from soil to the atmosphere in both field chamber and eddy flux methods, and a membrane inlet mass spectrometer to quantify dissolved N2 in water. There is immediate demand (and funding) for use and maintenance of the instrumentation for the ongoing long-term research at the Hubbard Brook and Baltimore LTER sites and the long-term environmental monitoring program at the Cary Institute. The Cary Institute nitrogen gas major measurement facility will be established under the supervision of Dr. Peter Groffman. The current lead research support specialist in Groffman's laboratory has over 10 years of experience in field and laboratory measurement of N gas fluxes and has trained numerous undergraduate, graduate and postdoctoral researchers. There is active collaboration among the senior research support specialists at the Cary Institute for allocation of space, training of new users and instrument maintenance and trouble-shooting. Much of this collaboration is managed by the institute-supported Director of Laboratory Facilities and Analytical Services, the Safety Officer and the Manager of the Cary Institute Environmental Monitoring program. For more information about the Carey Institute, visit http://www.caryinstitute.org/.