Semidirect dynamical and radiative effect of North African dust transport on lower tropospheric clouds over the subtropical North Atlantic in CESM 1.0

摘要: This study uses a century length preindustrial climate simulation by the Community Earth System Model (CESM 1.0) to explore statistical relationships between dust, clouds, and atmospheric circulation suggest semidirect dynamical mechanism linking subtropical North Atlantic lower tropospheric cloud cover with African dust transport. The of run allows us account for interannual variability emissions transport in model. CESM's monthly climatology both aerosol optical depth surface concentration at Cape Verde Barbados, respectively, agree well available observations, as does size distribution Verde. In addition, CESM shows strong seasonal cycles burden fraction, maximum values occurring during boreal summer, when correlation these two variables exists over Atlantic. Calculations Estimated Inversion Strength (EIS) composites EIS on high low downstream months summer reveal that is likely increasing inversion strength this region due solar absorption reflection. We find no evidence microphysical link clouds region. These results yield new insight an extensive period time into complex relationship which has previously been hindered spatiotemporal constraints observations. Our findings lay framework future analyses using different models submonthly data regions underlying dynamics.