Constraining regional fluxes of CO2 and CH4 over Canada by merging atmospheric and ground observations

通过合并大气和地面观测来限制加拿大上空二氧化碳和甲烷的区域通量

• 批准号: 327657-2006
• 负责人: Lin, John
• 金额: $ 1.54万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=397899
• 关键词: Constraining; regional; fluxes; CO2; CH4

Concerns over increases in atmospheric concentrations of greenhouse gases such as CO2 (carbon dioxide) and CH4 (methane) make it critically important to improve understanding of where, why, and at what rates these gases are exchanged between the land surface and the atmosphere. The key gap is our inability to merge observations in the atmosphere and on the ground, characterizing diverse spatio-temporal scales, with process-level biological knowledge. The objectives of this study are as follows: (1) Develop a land-atmosphere modeling system that can ingest both atmospheric and ground-based observations at multiple spatial and temporal scales. (2) Determine the locations, strengths, and reasons for fluxes of CO2 and CH4, the two major greenhouse gases, over Canada. The focus is on resolving regional scale (10~1000 km) fluxes over the continent, knowledge of which have been hampered by modeling systems that cannot interpret the highly varying atmospheric observations over the continent. State-of-the-art atmospheric models will be combined with biospheric models that are optimized against such datastreams as direct CO2/CH4 flux observations and forest inventory analyses, previously used in absence of the atmospheric observations. Thus the proposed modeling system assimilates both atmospheric and ground-based measurements, thereby yielding "best-guess" fluxes that are optimally consistent with both atmospheric and biospheric knowledge. The proposed research program will make steps forward in climate science: a more detailed knowledge of sources/sinks of current greenhouse gases leads to enhanced capability to project future climate. Furthermore, the proposed research program will contribute towards Canada's obligations under the Kyoto Protocol by building the foundation for quantifying and monitoring emissions of greenhouse gases.

对大气中二氧化碳(二氧化碳)和甲烷(甲烷)等温室气体浓度增加的担忧，使得提高对这些气体在陆地表面和大气之间交换的地点、原因和速率的理解至关重要。关键的差距是我们无法将大气层和地面上的观测结果与过程级别的生物学知识结合起来，表现出不同的时空尺度。本研究的目标如下：(1)开发一个可以在多个空间和时间尺度上接受大气和地面观测的陆地-大气模拟系统。(2)确定加拿大上空二氧化碳和甲烷这两种主要温室气体的通量的位置、强度和原因。重点是解决大陆上区域尺度(10~1000公里)的通量，由于模拟系统无法解释大陆上空高度变化的大气观测，对这些通量的了解一直受到阻碍。最先进的大气模型将与生物圈模型结合起来，生物圈模型针对以前在没有大气观测的情况下使用的直接二氧化碳/甲烷通量观测和森林资源清查分析等数据流进行了优化。因此，拟议的模拟系统吸收了大气和地面测量，从而产生了与大气和生物圈知识最佳一致的“最佳猜测”通量。拟议的研究计划将在气候科学方面向前迈进一步：更详细地了解当前温室气体的源/汇，有助于增强预测未来气候的能力。此外，拟议的研究计划将通过建立量化和监测温室气体排放的基础，为加拿大履行《京都议定书》规定的义务做出贡献。