Sun-induced chlorophyll fluorescence (SIF) is an electromagnetic signal emitted in the 650-850 nm spectral range by the chlorophyll-a of green plants. The SIF emission has a mechanistic link to photosynthesis and responds instantaneously to perturbations in environmental conditions such as light and water stress, which makes it a powerful proxy for plants' photosynthetic activity.
After decades of ground-based experiments, global measurements of SIF from space have been available since late 2011 from a number of space-based atmospheric spectrometers (GOSAT, SCIAMACHY, GOME-2, OCO-2 and, recently, TROPOMI). The global SIF data sets obtained from those missions have revealed the potential of the satellite-based SIF data sets to represent the photosynthetic activity of different ecosystems, including large crop belts worldwide, the Amazon rainforest and boreal evergreen forests.
In this seminar, we will provide an overview of the monitoring of SIF from space, including a discussion of the physiological relationships between SIF and photosynthesis, a description of the physical principles behind the measurement, a review of selected studies making use of SIF data in carbon cycle studies and a short presentation of the near-future observational scenario.