This Week in Science

Ruth Levy Guyer
1991 Science  
Shifting sands in the Sahara Desert he Sahara is the world's largest desert; its size fluctuates between about 7 and 9 million square kilometers. Images of the desert that reveal vegetation patterns, which are a direct reflection of rainfall, have been made by polar-orbiting meteorological satellites for the past decade. Between 1980 and 1990 many northward and southward shifts in the southern Saharan-Sahelian boundary have occurred. The year-by-year changes are described by Tucker et al. (page
more » ... 299) and provide a valuable framework against which future shifts between desertification and steppe formation (more arable land) can be assessed; it will take several decades worth of data to reveal major trends that are occurring in the world's deserts. The techniques that are described in this study are currently being applied to analyses of desertification elsewhere on the planet's surface.
doi:10.1126/science.1991.253.5017.twis fatcat:giikkernaraj5lswdd7yesb3wy