Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
Science. 2017 Oct 13;358(6360). doi: 10.1126/science.aam5747.
Quantifying gross primary production (GPP) remains a major challenge in global carbon cycle research. Spaceborne monitoring of solar-induced chlorophyll fluorescence (SIF), an integrative photosynthetic signal of molecular origin, can assist in terrestrial GPP monitoring. However, the extent to which SIF tracks spatiotemporal variations in GPP remains unresolved. Orbiting Carbon Observatory-2 (OCO-2)'s SIF data acquisition and fine spatial resolution permit direct validation against ground and airborne observations. Empirical orthogonal function analysis shows consistent spatiotemporal correspondence between OCO-2 SIF and GPP globally. A linear SIF-GPP relationship is also obtained at eddy-flux sites covering diverse biomes, setting the stage for future investigations of the robustness of such a relationship across more biomes. Our findings support the central importance of high-quality satellite SIF for studying terrestrial carbon cycle dynamics.
量化总初级生产力（GPP）仍然是全球碳循环研究中的主要挑战。卫星监测太阳诱导叶绿素荧光（SIF），这是一种分子起源的综合光合作用信号，可以辅助陆地 GPP 监测。然而，SIF 在多大程度上跟踪 GPP 的时空变化仍未得到解决。轨道碳观测站-2（OCO-2）的 SIF 数据采集和精细的空间分辨率允许与地面和空中观测进行直接验证。经验正交函数分析表明，OCO-2 SIF 和 GPP 在全球范围内具有一致的时空对应关系。在涵盖多种生物群落的涡度通量站点上也获得了 SIF-GPP 的线性关系，为未来在更多生物群落中研究这种关系的稳健性奠定了基础。我们的研究结果支持高质量卫星 SIF 在研究陆地碳循环动力学中的核心重要性。
