中国涡度相关通量塔空间代表性评估与碳源/汇尺度扩展研究

本项目通过引入通量足迹概率分布函数，依据对卫星遥感影像资料的空间分析及地统计分析，从中国现有98个通量塔中，选取大约1/3代表性的通量塔进行塔位误差分析和空间代表性评价；在此基础上，结合各种其它地基观测资料、多源多尺度卫星遥感反演的碳敏感参数，采用生态系统模型（自下而上）和一维大气传输反演模型（自上而下）数值模拟和数据-模型同化等方法，发展基于通量塔观测数据的碳源汇尺度扩展技术；定量估算多尺度（景观、区域、生物气候带和我国国家尺度）的碳源汇分布，揭示我国陆地生态系统近10年来时空动态变化规律；解决困扰世界碳循环领域中尺度转换的瓶颈问题，为我国政府参与政府间的应对气候变化谈判提供科学依据。

The proposed project plans to develop a pragmatic approach for evaluating the spatial representativeness and sensor location bias of flux tower measurements based on footprint climatology modeling and geo-statistical analyses using remote sensing image data (land cover, digital elevation model, vegetation indices, etc.). This approach will be applied to the selected representative flux towers for different bio-climate zones and vegetation function types from the total current 98 towers across China's landmass. Based on this and a variety of other ground-based measurements, carbon-sensitive parameters retrieved from multi-source and multi-scale remotely-sensed data, we will develop and improve an integrated approach involving numerical ecosystem modeling (bottom-up), atmospheric inversion using a one-dimensional atmospheric transport model (top-down), and data-model assimilation technics to scale up the estimation of carbon sources/sinks to the landscape, regional, bio-climatic zones and the national scales. The distributions and dynamics of carbon sources/sinks at varied spatial-temporal scales over the entire China landmass during the past 10 years will be quantitatively estimated. The implementation of this project will help remove a bottleneck of spatial scaling in carbon cycle research that limits the application of bottom-up approach for carbon budget. These will provide scientific supporting for China national carbon management and will provide scientific supports and benefit China government regarding climate-change related negotiation between governments.