Solar-Induced Fluorescence (SIF) Captured by California Laboratory for Atmospheric Remote Sensing (CLARS)

Abstract:

Solar-induced fluorescence (SIF) is emitted from the core of the photosynthetic apparatus and can serve as a direct indicator of photosynthetic efficiency. It could be exploited for large scale monitoring of plant health, which is crucial for studies in ecosystem, carbon cycle, agriculture, and other related fields. In this study, we use Fourier Transform Spectrometers at California Laboratory for Atmospheric Remote Sensing (CLARS) to measure high-resolution spectra near the oxygen A band. Measurement campaigns conducted in recent two years provide weeks of measurements that capture the diurnal variations of SIF from a variety of species including grasses and oak trees. Stationed on the top of Mount. Wilson in Southern California, CLARS is capable of monitoring SIF over the nearby mountains and the Los Angeles basin. This study aims to demonstrate that instruments at CLARS are capable of capturing SIF with high precision over different times of day. The high spatiotemporal variations of SIF are unique features of the CLARS measurements. The results have implications for the proposed constellation of geostationary satellites that are designed to capture SIF at regional scales.