Influence of winter Saharan dust on equatorial Atlantic variability

The equatorial Atlantic plays a critical role in regional and global climates, yet the influence of Saharan dust in this region remains underexplored. While Saharan dust’s effects on sea surface temperature variability in the North Tropical Atlantic are well-documented, its impact near the equator, particularly during boreal winter, when dust transport reaches its southernmost extent, has received limited attention. Using observational and reanalysis data, we investigate the effects of Saharan dust on equatorial Atlantic variability. We observe a distinct and complex response contrary to the expected cooling from reduced solar radiation. Dust-induced warming in the lower troposphere drives significant sea surface temperature warming off northwestern Africa through changes in latent heat fluxes and Ekman convergence, leading to an off-equatorial warm front. This warm front generates cross-equatorial winds that shift the Atlantic rain belt northward, cool the equatorial region, and trigger wave activity, ultimately causing delayed warming. This study highlights the need to understand complex dust-climate interactions, identifying Saharan dust as a potential driver of equatorial Atlantic variability with broader climatic implications.