The strength of El Nino and the spatial extent of tropical drought

[ 1] During El Nino events, several spatially coherent, nearly synchronous droughts typically develop in teleconnected tropical land areas. These droughts, reflected in below-average tropical mean land area precipitation, are frequently accompanied by multiple and wide ranging impacts. Here it is shown, based on precipitation observations for the past half-century, that there is a remarkably robust relationship between El Nino strength and the spatial extent of drought in the global tropics. Not reported previously, drought covers more than twice the land area in strong versus weak El Ninos and in many areas severe drought is shown to be more likely during El Nino than for all other times. The results provide insight into large-scale tropical rainfall variability and have implications for future droughts under global warming scenarios.