Climate model simulations analyzed as part of the study revealed that the relationship between sea surface temperatures and atmospheric convection in the Indian Ocean changes rainfall in East Africa. Specifically, wet conditions in coastal East Africa are associated with cool sea surface temperatures in the eastern Indian Ocean and warm sea surface temperatures in the western Indian Ocean, which cause ascending atmospheric circulation over East Africa and enhanced rainfall. The opposite situation—cold sea surface temperatures in the western Indian Ocean and warmer in the East—causes drought. Such variations in sea-surface temperatures likely caused the historical fluctuations in rainfall seen in the paleorecord. Image courtesy of Jessica Tierney, et al, 2013 (Click image to enlarge)