An observation-based estimate of the strength of rainfall-vegetation interactions in the Sahel

摘要: Over the course of twentieth century African Sahel experienced large variations in annual precipitation; including wet period during 1950s and 1960s long-term drought 1970s 1980s. Feedbacks between land surface atmosphere can affect rainfall variability at monthly, decadal time scales. However, strength coupling precipitation is still highly uncertain, with climate-model derived estimates differing by an order magnitude. Here a statistical model vegetation greenness used to estimate vegetation-rainfall Sahel, based on monthly satellite-derived index meteorological data. Evidence found for positive feedback scale, memory operating scale. These interactions increase interannual variation Sahelian accounting as much 30% some hot spot regions 15° 20°N.