Observed and Simulated Changes in Precipitation over Sahel Region of West Africa

Abstract

There is an increasing need for strategic evaluations of changes in precipitation in current and future conditions. The paper simulates West African Sahel region climatology, describing the major characteristic of precipitation variability and trends in the region. The study assess the changes in precipitation in Sahel region using observational data output from Global Precipitation Climate Centre (GPCC) and Climate Research Unit (CRU) data set together with General Climate Model (GCM) AR4 used by Intergovernmental Panel on Climate Change (IPCC) to investigate precipitation trends over the Sahel region. In West Africa, rainfall has been subject to large decadal and inters decadal variation. A period of (1910-2009, 2050-2080) was chosen to understand the climatic variability across the Sahel region. Mike Hulme in his paper described Sahel climate as the most dramatic example of climatic variability that the world has observed. It is consequently significance to understand if, and to which extent climate trends in the Sahel region exist that influence availability of water in future. The study demonstrates that the characteristics of rainfall variability in Sahel region differ markedly. The analyses show that the Northern part of the Sahel region is characterizes by low precipitation while the West Coast and Gulf of Guinea rainfall are apparent, although uncertainty from the GCM cannot be over role. The rationale behind the study is the need to understand the nature of climate change in the region over the past 100 years in relation to changes in precipitation together with the spatial pattern of these changes.