NOAA Satellites: Monitoring the Health of Global Vegetation from Space

The VH products can be used as proxy data for monitoring vegetation health, drought, soil saturation, moisture and thermal conditions, fire risk, greenness of vegetation cover, vegetation fraction, leave area index, start/end of the growing season, crop and pasture productivity, teleconnection with ENSO, desertification, mosquito-borne diseases, invasive species, ecological resources, land degradation, etc.

For over thirty years, Advanced Very High Resolution Radiometers (AVHRR) onboard NOAA's series of polar orbiting satellites have observed radiation levels from the earth's surface. These varying wavelengths, recorded on different channel bands by the AVHRR instrument, are used by scientists to monitor sea surface temperature, day and night cloud and surface mapping, and snow and ice detection.

By combining wavelengths from 4 channel bands, the visible (VIS), near infrared (NIR), and two infrared (IR) bands of the solar spectrum, scientists have been able to determine the relative health of ecosystems in given areas. For example, vegetation reflects little radiation in the VIS part of the solar spectrum due to high chlorophyll absorption and much radiation in the NIR band. Known as the Vegetation Health (VH) System and maintained on the NOAA website, these derived products serve as an online resource for monitoring environmental conditions and climate-dependent socioeconomic activities. Using the VH System, NOAA produces regional and global-scale estimations of drought, fire risk, soil saturation, and predicted outbreaks of malaria. Users of this data include governments, international relief organizations, private industry, and even farmers. Applications include agriculture, forestry, water usage, food supply/demand, environmental security, and trade. Approximately 2,200 users per month and over 60 different organizations link to the VH website.

Scientists in the NESDIS Center for Satellite Applications and Research (STAR), the National Center for Environmental Prediction, Environmental Modeling Center, and I.M. Systems Group contribute towards the development of the Global Vegetation Health Products. In addition to the observations from the NOAA polar-orbiting satellites, NOAA uses data and products from its geostationary satellites (GOES), the Defense Meteorological Satellite Program (DMSP), Europe (METEOSAT) and Japan (MTSAT).

To learn more, visit the NOAA VH product website or contact the lead NOAA scientist for VH, Dr. Felix Kogan.