US crop productivity, fluorescence satellite image. The red glow across North American represents fluorescence measured from land plants in early July, over a period from 2007 to 2011. The brightest area is in the US Midwest, in a region of high agricultural productivity known as the Corn Belt. The fluorescence emitted by the chlorophyll in healthy growing plants can be detected by satellites, even those not primarily designed for this purpose. The data is from the Global Ozone Monitoring Experiment 2 (GOME-2) on the Metop-A meteorological satellite. The results of the research were published in 2014.