Satellite data can be used to monitor the health of plant life from space. The Normalized Difference Vegetation Index (NDVI) provides a simple numerical indicator of the health of vegetation which can be used to monitoring changes in vegetation over time. This animation shows the seasonal changes in vegetation by fading between average monthly NDVI data from 2004. This animation of land changes is match framed to animation id a003708, a003709, a003710, and a003711.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 188.8.131.52.0