The impact of the Agulhas Current system on precipitation in southern Africa in regional climate simulations covering the recent past and future

Abstract

The southern African climate is strongly impacted by climate change. Precipitation is a key variable in this region, as it is linked to agriculture and water supply. Simulations with a regional atmospheric model over the past decades and the 21st century display a decrease in the past precipitation over some coastal areas of South Africa and an increase over the rest of southern Africa. However, precipitation is projected to decrease over the whole southern part of the domain in the future. This study shows that the Agulhas Current system, including the current and the leakage, which surrounds the continent in the east and south, impacts this precipitation trend. A reduction in the strength of the Agulhas Current is linked to a reduction in precipitation along the southeast coast. The Agulhas leakage, the part of the Agulhas Current that leaves the system and flows into the South Atlantic, impacts winter precipitation in the southwest of the continent. A more intense Agulhas leakage is linked to a reduction in precipitation in this region.