First Global Retrievals of Solar Induced Chlorophyll Fluorescence From the SIFIS Instrument Onboard the Chinese Goumang Satellite

Abstract In recent years, solar‐induced chlorophyll fluorescence (SIF) has shown great potential for monitoring terrestrial photosynthesis, but existing satellite SIF retrievals typically feature coarse spatial resolutions on the order of kilometers or larger. Recently, the Chinese Terrestrial Ecosystem Carbon Inventory Satellite, Goumang, launched in August 2022, carries a unique SIF Imaging Spectrometer (SIFIS), the first spaceborne sensor especially designed for global SIF retrieval. SIFIS provides a high spatial resolution (370 × 800 m) and high spectral resolution (0.24, 664–786 nm), enabling the same order of SIF retrieval error (∼0.48 mW/m 2 /nm/sr) as other satellite SIF products. The SIFIS radiance measurement and SIF retrievals were first validated using the airborne AisaIBIS data. SIFIS SIF showed high spatial and temporal agreement with independent satellite SIF data sets and high correlations with flux tower estimates of gross primary production (R 2 = 0.87). This new SIF product opens new avenues for studying fine‐scale photosynthesis from space.