Scientists use satellites to map glowing plants
Plants convert the Sun’s energy into chemical energy through the process of photosynthesis. The amount of photosynthesis taking place can be a good indicator of how healthy a plant and its environment are.
During the process of photosynthesis, a small amount of light, invisible to the human eye, is emitted by the plant. This glow is called fluorescence, and ample fluorescence can show that the plant is thriving.
NASA scientist Joanna Joiner and her team at Goddard Space Flight Center in the United States produced maps of this glow, using data from the Global Ozone Monitoring Instrument 2 (GOME-2) on Metop-A. The particular light from fluorescence was difficult to isolate from reflected sunlight. Some light is also absorbed by gases in the atmosphere.
However, once the fluorescence was identified, the researchers could see evidence of the change of seasons through the output of the plants.
The new NASA OCO-2 satellite will also help to map fluorescence, whilst its main mission is to measure atmospheric carbon dioxide.