NDVI values vary with absorption of red light by plant chlorophyll and the reflection of infrared radiation by water-filled leaf cells. IPAR and hence NDVI is correlated with photosynthesis. Because photosysthesis occurs in the green parts of plant material the NDVI is normally used to estimate green vegetation. This sample greenness image was composited over the 14-27 December 1996. The ocean is shown black, areas affected by cloud are masked white.
Red indicates low greenness, through yellow, green blue to purple which indicates high greenness.
Cloud affects a significant area of the tropical North in this image.