Collaborative Research: ETBC--The Cycling of Nitrogen in an Earth System Model: Constraints and Implications for Climate Change

合作研究：ETBC——地球系统模型中的氮循环：气候变化的约束和影响

• 批准号: 1020767
• 负责人: Gordon Bonan
• 金额: $ 42.57万
• 依托单位: University Corporation For Atmospheric Res
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1020767&HistoricalAwards=false
• 关键词: Collaborative; Research; ETBC; Cycling; Nitrogen

The overarching goals of this project are: 1) to constrain the global budget of reactive nitrogen (Nr) through a combination of numerical simulations, data synthesis and analysis; and 2) to produce initial estimates of the overall interaction between reactive nitrogen cycling and climate. The nitrogen cycle is a key regulator of the Earth's climate system, linking terrestrial, marine, photochemical, and industrial processes, and modulating the carbon cycle. Over the last century and a half, expansion and intensification of agriculture and fossil fuel combustion have led to a more than doubling of Nr emissions to the atmosphere with profound impacts on the earth system. A closed global Nr cycle will be simulated within the CCSM (Community Climate System Model) by tracking Nr across three model domains: (1) atmosphere, (2) land, including native and agroecosystems, and (3) fresh and oceanic waters. While the basis for much of this work has already been developed within the CCSM, the nitrogen cycle has not been coupled across the different model domains. In the fully coupled system, each model domain will simulate the transport and production of Nr within its domain and the chemistry and loss of Nr from its domain, with the requirement that the nitrogen fluxes between the domains be self-consistent. This mass-balanced approach will avoid the untracked losses of Nr that occur when the nitrogen cycle is modeled in isolation within a single domain. Moreover, it will consider the diverse and opposing impacts of Nr on terrestrial carbon sinks and on the radiatively important species nitrous oxide, ozone, methane and aerosol ammonium sulfate. It is hypothesized that the overall effect of a changing Nr cycle on these four atmospheric species will lead to a warming sufficient to offset the cooling associated with increased Nr availability and increased terrestrial carbon uptake.The synthesized datasets for evaluating the nitrogen cycle in Earth System Models, the coupled nitrogen-carbon-climate model developed here, and the simulations with the CCSM will be made broadly available to university and national laboratory communities and will contribute to the upcoming IPCC 5th Assessment. Most of the principal investigators in this project are actively engaged in graduate student education and training, and most participate in undergraduate activities as well. The research will support four additional graduate students and one postdoctoral associate as well as a number of undergraduates. All will become involved in the research activities both at their respective local institutions, as well as across all institutions and disciplines involved in the project.

该项目的总体目标是：1）通过数值模拟，数据综合和分析的组合来限制反应氮（NR）的全球预算； 2）产生反应性氮循环和气候之间总体相互作用的初步估计。氮循环是地球气候系统的关键调节剂，它连接了陆地，海洋，光化学和工业过程，并调节了碳循环。在上个世纪半，农业和化石燃料燃烧的扩张和强化导致NR排放量增加了一倍以上，对地球系统产生了深远的影响。通过在三个模型域中跟踪NR，将在CCSM（社区气候系统模型）中模拟封闭的全球NR周期：（1）气氛，（2）土地，包括天然和农业生态系统，以及（3）新鲜和海洋水域。尽管这项工作的大部分基础已经在CCSM内开发，但氮循环尚未在不同的模型域中耦合。在完全耦合的系统中，每个模型域将模拟其域内NR的运输和生产，以及从其域中的化学和NR的损失，并要求域之间的氮通量是自吻的。这种质量平衡的方法将避免在单个域内隔离氮循环建模时发生的NR的未跟踪损失。此外，它将考虑NR对陆生碳水槽以及辐射重要的物种一氧化二氮，臭氧，甲烷和气溶胶硫酸铵的多种影响和相反的影响。据推测，NR周期变化对这四种大气物种的总体影响将导致足以抵消与NR可用性增加和陆地碳摄取增加相关的冷却，以评估地球系统中的氮循环，与nientrogen-climate con-COCM MADE MASS MASS MASS MASS MASS MASM MASS MASM MASS MASM MASM MASM MASM MASM MASM MASM MASM MASM INTHRONTRATY数据集。社区，将为即将进行的IPCC第五评估做出贡献。该项目中的大多数主要研究人员都积极从事研究生教育和培训，并且大多数还参加了本科活动。该研究将支持另外四名研究生和一名博士后同学以及许多本科生。所有人都将参与各自当地机构，以及该项目所涉及的所有机构和学科的研究活动。