Current research suggests that climate change and continued anthropogenic forcing of the climate system may increase the occurrence of extreme events such as droughts in the near future. Prolonged droughts are potentially destructive because of widespread impacts and difficulty in prediction. In addition, droughts interact in complex ways with vegetation systems, inducing abrupt rather than gradual changes in vegetation. Using satellite and station rainfall data, this research seeks to identify patterns in drought and vegetation change on a global scale and in the tropics (15ºN to 35ºS), where precipitation is the predominant determinant of climate. It is observed that long drought occurs in regions of variability in vegetation. Additionally, long drought is observed in regions on the fringe between dominant vegetation types of desert, grassland, and forest. These results suggest that prolonged drought may be a significant contributor to abrupt vegetation changes. The other part of this study is a regional investigation of vegetation change and drought in the Congo Basin. The correlation between drought and forest loss in the Congo is not clear. Preliminary studies of the atmospheric mechanisms governing drought in the Congo are presented. The results of this work as a whole will provide a better understanding of drought patterns and vegetation responses to drought, ultimately to provide better adaptation to a more extreme future climate.Geological SciencesPhysic