Interpretation and implication of canopy diurnal fluorescence by the field automatic measurment system

Solar-induced chlorophyll fluorescence (SIF) has been considered a direct proxy in monitoring vegetation actual photosynthesis. However, applications in the Earth science have been greatly limited due to challenges in use of remotely sensed SIF. This is because the linkage between vegetation actual photosynthesis and SIF retrieved from the canopy reflected radiance exists numerous uncertainties. It is reported that ground-based long-term SIF measurement system can promote the understanding of diurnal and seasonal dynamics of vegetation SIF. This study investigates the interpretation and implication of remotely retrieved canopy diurnal SIF using a newly developed automated SIF field measurement system (Auto-SIF system) in China, involving different vegetation types, data acquisition frequencies and weather conditions. Results may improve the understanding of both vegetation SIF and photosynthesis, thus further boosting the applications of SIF.