Stratospheric impacts on dust transport and air pollution in West Africa and the Eastern Mediterranean

Saharan dust intrusions significantly impact Atlantic and Mediterranean coastal regions. This study demonstrates that North African dust emission and transport are influenced by sudden stratospheric warmings (SSWs) on timescales of weeks to months, establishing a negative North Atlantic Oscillation-like surface signal. Chemical transport models reveal a dipolar dust response to SSWs, with increased dust in the Eastern Mediterranean (up to 30%) and reduced dust in West Africa. Observations confirm this dipole pattern. On average, a single SSW causes increased premature deaths in the Eastern Mediterranean and prevents premature deaths in West Africa due to changes in PM2.5 concentrations. The predictability of SSWs (1-2 weeks in advance) highlights the stratosphere's role in subseasonal air quality forecasting for West Africa and the Eastern Mediterranean.

Ying Dai, Peter Hitchcock, Natalie M. Mahowald, Daniela I. V. Domeisen, Douglas S. Hamilton, Longlei Li, Beatrice Marticorena, Maria Kanakidou, Nikolaos Mihalopoulos, Adwoa Aboagye-Okyere