Tracking Photosynthesis from Space

Professor Paul Wennberg and colleagues have developed a new technique to analyze plant productivity using data from NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite. To perform photosynthesis, the chlorophyll in leaves absorbs sunlight and a small fraction of the absorbed light is reemitted as near-infrared light. This reemitted light makes the plants appear to glow—a property called solar induced fluorescence (SIF). "The measurements of SIF from OCO-2 greatly extend the science of this mission", says Professor Wennberg. "OCO-2 was designed to map carbon dioxide, and scientists plan to use these measurements to determine the underlying sources and sinks of this important gas. The new SIF measurements will allow us to diagnose the efficiency of the plants—a key component of the sinks of carbon dioxide." [Caltech story]