The magnitude of fluorescence portrayed in this visualization prompted researchers to take a closer look at the productivity of the U.S. Corn Belt. The glow represents fluorescence measured from land plants in early July, over a period from 2007 to 2011. Image credit: NASA’s Goddard Space Flight Center
› Larger image
Data from satellite sensors show that during the Northern Hemisphere’s growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.
Healthy plants convert light to energy via photosynthesis, but chlorophyll also emits a fraction of absorbed light as a fluorescent glow that is invisible to the naked eye. The magnitude of the glow is an excellent indicator of the amount of photosynthesis, or gross productivity, of plants in a given region.
Research in 2013, led by Joanna Joiner of NASA’s Goddard Space Flight Center in Greenbelt, Md., demonstrated that fluorescence from plants could be teased out from existing data from satellites that were designed and built for other purposes. The new research, led by Luis Guanter of the Freie Universität Berlin, used the data for the first time to estimate photosynthesis from agriculture. Results were published March 25 in the Proceedings of the National Academy of Sciences.
According to co-author Christian Frankenberg of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., “The paper shows that fluorescence is a much better proxy for agricultural productivity than anything we’ve had before. This can go a long way regarding monitoring — and maybe even predicting — regional crop yields.”