Angola rainfall reconstruction and rainfall variability during the war period: 1979-2003

Abstract

The Republic of Angola has a dramatic lack of in situ precipitation and temperature data since 1979 up to 2003 due to a civil war. Due to this fact, there are only a few and old studies about the climate of the region being the improvement of the state of the Art of the rainfall climatology and its variability, a hot point for the understanding of the tropical climate. The period without data occurs after the climate shift of the 70’s, for which important changes in the global climate have been documented. For all these reasons, the reconstruction of the Angola precipitation timeseries is of great interest. Using the commonly used methodology of statistical downscaling, the 1979- 2003 rainfall timeseries have been reconstructed for the rainy season, taking into account the available atmospheric information from the NCEP reanalysis and documented teleconnection indices with an important influence in Southern African continent. Also, new indices have been calculated on the basis of the teleconnections established with the available data and the analysis of the work done by other authors. The variability of the reconstructed precipitation has been characterized by calculating the principal modes of the anomalous rainfall and a comparison with a satellite-based rainfall data set has been also performed. The information obtained in this study is very useful and adds new insight for the improvement of the knowledge of the Angola climatology and its variability.