NACP North American 8-km Net Ecosystem Exchange and Component Fluxes, 2004

This data set provides modeled carbon flux estimates at 8-km spatial resolution over North America for the year 2004 of (1) net ecosystem exchange (NEE) of carbon dioxide (CO2), (2) net ecosystem production (NEP, the balance of net primary production and heterotrophic respiration), (3) stream evasion (CO2 emitted from streams and rivers), (4) emissions from harvested forest and agricultural products, and (5) emissions from biomass burning. Annual estimates, in g C/m2/year, are provided for all five fluxes. Daily estimates, in g C/m2/day, are provided for NEP and stream evasion fluxes. Fluxes for fire emissions, harvest decomposition/respiration, stream evasion, and NEP were derived as described in Section 5. NEE fluxes were estimated using a full bottom-up accounting of NEE produced by integrating emissions from harvested forest and agricultural products, CO2 emitted from streams and rivers, and biomass burning in the CarbonTracker (version 2011_oi) modeling system. NEE estimates were run in the forward mode through the CarbonTracker inversion setup that calculates CO2 uptake and release at the Earth's surface over time. Refer to Turner et al.(2013) for details. There are seven data files in NetCDF (.nc) format with this data set, including: five annual files for fire emissions, harvest decomposition/respiration, stream evasion, NEP, and NEE fluxes; and two daily files for NEP and stream evasion fluxes.本数据集提供了2004年北美区域8千米空间分辨率的模拟碳通量估算结果，涵盖以下5类通量：(1) 二氧化碳（CO₂）净生态系统交换（net ecosystem exchange, NEE）；(2) 净生态系统生产力（net ecosystem production, NEP，即净初级生产与异养呼吸的平衡量）；(3) 河流逸出（stream evasion，指溪流与河流排放的CO₂）；(4) 采伐林产品与农产品产生的排放；(5) 生物质燃烧排放。 所有5类通量均提供以g C/m²/年为单位的年际估算结果；其中净生态系统生产力与河流逸出通量额外提供以g C/m²/天为单位的日度估算结果。 火灾排放、采伐分解/呼吸、河流逸出以及净生态系统生产力这四类通量的计算方法详见第5章节。 二氧化碳净生态系统交换通量的估算采用自下而上的完整核算方法：整合采伐林产品与农产品排放、溪流与河流排放的CO₂以及生物质燃烧排放，将其纳入CarbonTracker（版本2011_oi）模型系统进行计算。净生态系统交换通量的估算通过CarbonTracker反演框架以正向模式运行，该框架可实时计算地球表面的CO₂吸收与释放量。具体细节可参考Turner等人2013年的研究成果。 本数据集包含7个NetCDF（.nc）格式的数据文件，具体包括：5个对应火灾排放、采伐分解/呼吸、河流逸出、净生态系统生产力以及净生态系统交换通量的年际数据文件；以及2个对应净生态系统生产力与河流逸出通量的日度数据文件。