North African dust transport toward the western Mediterranean basin: atmospheric controls on dust source activation and transport pathways during June–July 2013

摘要: Abstract. Dust transported from north African source region toward the Mediterranean basin and Europe is a ubiquitous phenomenon in region. Winds formed by large-scale pressure gradients foster dust entrainment into atmosphere over regions advection of downwind. The constellation centers high low determines wind speed direction, thus chance for emission northern Africa transport Mediterranean. We present characteristics atmospheric life cycle determining with focus on ChArMEx (Chemistry-Aerosol Experiment) special observation period June July 2013 using atmosphere–dust model COSMO-MUSCAT (COSMO: COnsortium Small-scale MOdeling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model). Modes circulation are identified empirical orthogonal function (EOF) analysis geopotential height at 850 hPa compared to EOFs calculated 1979–2015 ERA-Interim reanalysis. Two different phases first EOF, which total explain 45 % variance. They characterized propagation subtropical ridge basin, position Saharan heat predominant Iberian low, discussed illustrating dipole pattern enhanced (reduced) fluxes, stronger (weaker) meridional transport, consequent increased (decreased) concentrations deposition fluxes. In event high-pressure zone western central (positive phase), hot spot flux evident Grand Erg Occidental, reduced level loading occurs basin. northward direction due prevailing northerly winds. case trough linking (negative southerly winds resulting an Altogether, results this study illustrate relevance knowing location concert circulation. elaborates question variability summertime regard conditions controlling routes dust, exemplarily 2-month June–July 2013. Ultimately, outcomes contribute understanding variance populated