Variability and trends of atmospheric moisture in recent West African monsoon season and the Coordinated Regional Downscaling Experiment‐Africa projected 21st century scenarios

Abstract

The interannual variability and trends of atmospheric moisture flux convergence (MFC) and the flux transport and their roles in wet season rainfall variability during the West Africa monsoon season have been investigated using the Climate Research Unit observational datasets and the National Center for Environmental Prediction reanalysis 2 from 1979 to 2016 and the Coordinated Regional Downscaling Experiment (CORDEX)‐Africa model outputs. Particular emphasis has been placed on the three rainfall zones: the Western Sudano Sahel, the Eastern Sudano Sahel and the Guinea Coast. The MFC shows largest variability and impact on rainfall in the Western Sudano Sahel, followed by the Guinea Coast, but there is no significant impact in the Eastern Sudano Sahel. Furthermore, the MFC shows significant positive trends at the Sahelian locations but not at the Guinea Coast. The CORDEX‐Africa models adequately simulate the climatology and spatial patterns of the mean June to September atmospheric moisture; however, differences exist in the magnitude and signs of the temporal trend. The model ensemble mean is presented, which better represents the atmospheric moisture during the monsoon rainfall variability. A mean bias‐corrected projection of the atmospheric moisture shows enhanced rainfall variability of the Guinea Coast in the representative concentration pathway (RCP) 4.5 and RCP 8.5 at the end of the 21st century.

Potential Impacts of Climate Change on the Sudan-Sahel Region in West Africa - Insights from Burkina Faso

“…Additionally, the number of heavy rainfall events in the country is likely to increase (Fig.SI.2; Supporting Information). The increase in RX5days, RR20mm and RX1day could be related to the availability of moist air in a warmer atmosphere, as the convergence of atmospheric moisture fluxes in the central Sahel is expected to increase with global warming (Okoro et al, 2020). Population growth, land use, and land cover change have been also identified as factors that may contribute to the increase in heavy rainfall and flooding in Burkina Faso (Sougué et al, 2023;Tazen et al, 2019).…”

Environmental risk assessment of the intake of contaminants in aquifers in the vicinity of a reclaimed waste dumpsite in Owerri municipal, Southeastern Nigeria

“…The wet period usually begins from March to October with the mean yearly rainfall estimated at 2500-4000 mm. About 89% of the rainfall is witnessed between May and October (Okoro et al 2014(Okoro et al , 2019. The regularity and intensity of the rainfalls result in massive runoff occasioned by the presence of steep slopes which renders the area vulnerable to flooding.…”