Rainfall variability in the Republic of Congo

In this book, an analysis is undertaken of the relationships between rainfall variability in the Republic of Congo and atmospheric and oceanic dynamics. Three types of indices are used: rainfall indices (North-Congo Index, Centre-Congo Index, South-Congo Index); oceanic indices: AMO (Atlantic Multi-decadal Oscillation), NAO (North Atlantic Oscillation), SOI (Southern Oscillation Index) and Nino3_4; atmospheric indices (geopotential at 1000 hPa). The evolution of annual and seasonal precipitation shows a significant downward trend since 1980. Parametric and non-parametric tests (Mann-Kendall, Pettitt, Buishand, Hubert) confirm 1970 as the year of break in the precipitation time series. Two major periods stand out: 1950-1970 (wet) and 1971-2005 (dry). The canonical correlations between rainfall indices, oceanic indices and atmospheric indices on an annual and seasonal scale reveal a relatively strong link, materialized by significant correlations.