BIOCOMPLEXITY: Collaborative Research: Oceanic N2 fixation and Global climate

生物复杂性：合作研究：海洋 N2 固定和全球气候

• 批准号: 9981662
• 负责人: Edward Carpenter
• 金额: $ 20万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9981662&HistoricalAwards=false
• 关键词: BIOCOMPLEXITY; Collaborative; Research; Oceanic; N2

Oceanic nitrogen (N2) fixation has recently been identified as a significant part of theoceanic nitrogen (N) cycle and may directly influence the sequestration of atmospheric CO2 inthe oceans by providing a new source of N to the upper water column. The prokaryoticmicroorganisms that convert N2 gas to reactive N are an unique subcomponent of planktonicecosystems and exhibit a variety of complex dynamics including the formation of microbialconsortia and symbioses and, at times, massive blooms. Accumulating evidence indicates thatiron (Fe) availability may be a key controlling factor for these planktonic marine diazotrophs.The primary pathway of Fe delivery to the upper oceans is through dust deposition.N2 fixers may therefore be directly involved in global feedbacks with the climate systemand these feedbacks may also exhibit complex dynamics on many different time-scales. The hypothesized feedback mechanisms will have the following component parts: The rate of N2fixation in the world's oceans can have an impact on the concentration of the greenhouse gas,carbon dioxide (CO2), in the atmosphere on time-scales of decades (variability in surfacebiogeochemistry) to millennia (changes in the total NO3 - stock from the balance of N2 fixationand denitrification). CO2 concentrations in the atmosphere influence the climate. The climatesystem, in turn, can influence the rate of N2 fixation in the oceans by controlling the supply of Feon dust and by influencing the stratification of the upper ocean. Humans also have a direct rolein the current manifestation of this feedback cycle by their influence on dust production, throughagriculture at the margins of deserts, and by our own production of CO2 into the atmosphere.The circular nature of these influences can lead to a feedback system, particularly on longer time-scales.This collaborative and interdisciplinary group of investigators, led by Dr. Anthony Michaels, will study each of the components of this system and then to model the hypothesized feedback processes. Because of the interaction of the various parts of this system, keyed around the unique behavior and biogeochemistry of the prokaryotic microorganisms that can fix N2, this feedback loop should exhibit complex behaviors on a variety of time-scales. In this research, we will conduct a targeted series of experiments and field observations to understand and parameterize each of the pieces of this global process including the direct control of marine N2 fixation by dust deposition. This understanding will then feed a modeling process that examines the complex dynamics of this system on time-scales of years to millennia. The modeling process will be evaluated by comparison with data on the time-dependent behavior of ocean biogeochemistry

海洋氮（N2）固定最近已被确定为Theoceanic氮（N）循环的重要一部分，并通过向高层水柱提供新的N来源来直接影响海洋中大气CO2的隔离。将N2气体转换为反应性n的实质性极体是浮游生物系统的独特子组成部分，并且表现出各种复杂的动力学，包括形成微生物质体和共生性，有时甚至是巨大的开花。积累的证据表明，铁（FE）的可用性可能是这些浮游海洋重氮植物的关键控制因素。因此，向上海的Fe传递到上海的主要途径是通过尘埃沉积。 The hypothesized feedback mechanisms will have the following component parts: The rate of N2fixation in the world's oceans can have an impact on the concentration of the greenhouse gas,carbon dioxide (CO2), in the atmosphere on time-scales of decades (variability in surfacebiogeochemistry) to millennia (changes in the total NO3 - stock from the balance of N2 fixationand denitrification).大气中的二氧化碳浓度会影响气候。反过来，气候系统可以通过控制Feon粉尘的供应和影响上海的分层来影响海洋中N2固定的速率。人类还具有直接的角色，即通过对粉尘生产的影响，在沙漠边缘的努力以及我们自己的二氧化碳生产到大气中的影响，这些反馈周期的当前表现。这些影响的循环性质可以导致反馈系统，尤其是在较长的时间范围内，这些系统的合作和跨学科的人群，由调查人员组成的组合，构成了米密歇根州博士，构成了米尔西尔斯博士，构成了米尔西尔斯博士，构成了米密歇根州的构图，构成了米密歇根州的构图，构成了米尔米尔博士。假设的反馈过程。由于该系统的各个部分的相互作用，围绕可以修复N2的原核生物的独特行为和生物地球化学的关键，因此此反馈回路应在各种时间范围内表现出复杂的行为。在这项研究中，我们将进行一系列有针对性的实验和现场观测值，以了解和参数化全球过程的每个部分，包括通过尘埃沉积对海洋N2固定的直接控制。然后，这种理解将为建模过程提供一个建模过程，该过程检查了该系统的复杂动态，以数年的时间尺度到千年。建模过程将通过与海洋生物地球化学时间相关行为的数据进行比较来评估