遥感土壤水分与CO2柱浓度联合同化的陆地生态系统碳通量时空特征研究

Terrestrial carbon fluxes control global carbon budget. Precise estimation of the terrestrial carbon fluxes plays a vital role in carbon cycle. Recently, remotely sensed soil moisture and atmospheric CO2 concentrations have been widely used for better estimation of terrestrial carbon fluxes. Previous studies indicated that due to the implementation of simplified terrestrial biosphere models and the uncertainties in observations, terrestrial carbon fluxes that derived from the satellite-based carbon cycle data assimilation system has large uncertainties in spatial and temporal distributions. This proposed project will combine the remotely sensed soil moisture and atmospheric CO2 concentrations to constrain carbon fluxes simulated by a state-of-the-art terrestrial biosphere model coupled with the atmosphere transport model within the carbon cycle data assimilation system. The research will focus on: (1) terrestrial ecosystem carbon fluxes optimization; (2) the influences of soil moisture assimilation on terrestrial ecosystem carbon cycle; and (3) the spatial and temporal characteristics of the optimized global carbon fluxes. The outcomes of this project will improve understanding the relationships between soil moisture and terrestrial carbon cycle from the aspects of both science and practice.

陆地生态系统碳通量控制着全球碳平衡，其准确估算有助于生态系统碳循环研究的深入开展。近年来，基于遥感观测土壤水分及大气CO2柱浓度的陆地生态系统碳通量优化工作得到广泛开展。研究表明，由于生态系统模型简单、观测数据不足及空间分辨率过低等问题，基于遥感观测数据同化的陆地生态系统碳通量在时空分布上仍存在着较大不确定性。针对这一问题，本项目拟改进全球碳同化系统CCDAS，耦合大气传输模型，提高生态系统模型代表性；利用遥感观测的土壤水分和大气CO2柱浓度开展联合同化，(1)优化全球不同地区生态系统碳通量；(2)阐明土壤水分同化对生态系统碳循环的影响；(3)明确全球碳通量的时空特征。成果对更好地研究土壤水分与陆地碳循环的关系具有重要的科学意义和应用价值。

陆地生态系统碳通量控制着全球碳平衡，其准确估算有助于生态系统碳循环研究的深入开展。近年来，基于遥感观测土壤水分及大气CO2柱浓度的陆地生态系统碳通量优化工作得到广泛开展。研究表明，由于生态系统模型简单、观测数据不足及空间分辨率过低等问题，基于遥感观测数据同化的陆地生态系统碳通量在时空分布上仍存在着较大不确定性。针对这一问题，本项目拟改进全球碳同化系统CCDAS，耦合大气传输模型，提高生态系统模型代表性；利用遥感观测的土壤水分和大气CO2柱浓度开展联合同化，(1)优化全球不同地区生态系统碳通量；(2)阐明土壤水分同化对生态系统碳循环的影响；(3)明确全球碳通量的时空特征。成果对更好地研究土壤水分与陆地碳循环的关系具有重要的科学意义和应用价值。