[A-CG39] Biogeochemical cycles in Land Ecosystem

[ACG39-08] The structural and plant physiological effect on canopy-leaving solar-induced chlorophyll fluorescence (SIF) on estimating gross primary productivity of a larch forest

*Tomoki Morozumi¹, Hibiki M Noda¹, Tomomichi Kato², Hideki Kobayashi³, Yuma Sakai⁴, Yoshiyuki Takahashi¹ (1.National Institute for Environmental Studies, 2.Hokkaido University, 3.Japan Agency for Marine-Earth Science and Technology, 4.National Institute of Technology Tomakomai Colledge)

Keywords:optical remote sensing, continuous observation, canopy radiative transfer model

Solar-Induced chlorophyll Fluorescence (SIF) is related to the photosynthetic processes and is dynamic on an hourly scale responding to gross primary production (GPP). Remotely sensed SIF emitted above the canopy also depends on the canopy structure as described such as the clumping effect. To apply it to the study of the terrestrial carbon cycle, it is important to explore the physiological information within SIF. The 3-D canopy radiative transfer model can explicitly simulate SIF processes and is expected to split the canopy’s structural and physiological effects. The aim of the study is to evaluate the physiological-related SIF-GPP relationship based on a modeling approach for structural effects. The continuous SIF measurement was conducted using a fine spectroradiometer in 2020-2021 on the tower of the FHK flux site in central Japan. The FLiES-SIF model treated the light traveling within relatively sparse tree stands using the input of in-situ leaf-level full-spectral fluorescence yield measured by leaf clip. We present the SIF-GPP relationship among various meteorological conditions. The study further demonstrates the canopy structure effect on tower and satellite observation with various solar and observing angles. The result will be further applied to the regional GPP estimation via satellite SIF observations and models.