Experimental studies on long-range transport of aerosols in the troposphere

The presented work focuses on the experimental investigation of atmospheric aerosols of various origins. Main objectives are the characterisation of aerosols and their impact on climate. The first key topic is the effect of ageing and dilution of forest fire aerosol layers during long-range transport from the U.S. to Europe and the transformation of anthropogenic aerosols from urban pollution during atmospheric transport. For that purpose, observations from airborne measurements onboard the Falcon research-aircraft during the ITOP (Intercontinental Transport of Ozone and Precursors) field experiment in July 2004 are being analysed. The second key topic is the investigation of microphysical, optical and radiative properties of desert dust aerosols over source regions, as well as the modification of these dust properties during atmospheric transport from the source region to the far field and mixing with biomass burning aerosols. Information on these properties of aerosols are very important for satellite validation purposes (ENVISAT, ESSP 3/CALIPSO), for meso- and global-scale models and essential for the assessment of the impact of desert dust on climate. The information on the effects of transformation and mixing processes during long-range transport is urgently needed for an assessment of the impact of desert dust on the composition of the tropospheric aerosol and on heterogeneous chemical processes. To this aim, airborne in-situ measurements of desert dust aerosols in the vertical column over a source region and during long-range transport will be carried out during the German SAMUM (SAharan Mineral dUst experiMent) project