Influence of Chlorophyll Fluorescence on the Retrieval Accuracy of Carbon Dioxide

As a major error of CO2 retrieval, atmospheric scattering effect hampered the accuracy of CO2 retrieval. The stability of oxygen in the atmosphere is used in scattering correction for atmospheric CO2 inversion, such as the photon path length probability density function (PPDF) method. However, the presence of plant chlorophyll fluorescence in the light irradiation of O-2 A will affect the PPDF parameter retrieval as well as the accuracy of CO2 inversion. As the vegetation fluorescence is weak, in the previous CO2 inversion did not cause enough attention. Based on the study of global vegetation fluorescence distribution, the influence of fluorescence on atmosphere CO2 column content (XCO2) was simulated and analyzed. The influence of fluorescence under the aerosol free, aerosol and surface albedo condition is simulated, the result indicates that when the aerosol is not taken into account, the fluorescence intensity increases from 0. 1 to 1.8, which results in a deviation of 0. 1 to 2 (10(-6)) for the inversion of XCO2. Inversion of XCO2 results in a deviation of 0. 1 to 3 (10(-6)) when considering the influence of aerosol and surface reflectance. This research shows that chlorophyll fluorescence cannot be neglected in high precision CO2 inversion.