|
|
|
Earth is Becoming a Greener Greenhouse The Data: A 15-day global data set at 8 km resolution for the period July 1981 to December 1999 produced by the Global Inventory Monitoring and Modeling Systems (GIMMS) group at NASA Goddard Space Flight Center, from the Advanced Very High Resolution Radiometers (AVHRR) onboard the afternoon-viewing NOAA series satellites (NOAA 7, 9, 11 and 14) was used in this study. The important data processing features included improved navigation, sensor calibration, and atmospheric correction for stratospheric aerosols. The Normalized Difference Vegetation Index (NDVI) is expressed on a scale between -1 to +1, and ranges between -0.2 and 0.1 for snow, inland water bodies, deserts, and exposed soils, and increases from about 0.1 to 0.7 for increasing amounts of vegetation. A color coded image of annual average NDVI depicting the global vegetation greenness is shown below.
|
|
Sep-04-2001 |
