Abstract
This seminar will present a summary of the main results obtained during the ADABBOY project (African Dust and Biomass Burning Over the Yucatan) carried out between January 2017 and August 2018 at two sites (urban vs. rural) in the Yucatan Peninsula. Mostly clean conditions are observed at this fairly pristine site, due to predominant winds from the surrounding seas. Nevertheless, the peninsula is located at the crossroads of pollution from seasonal emissions of local and regional biomass burning and from long-range transport of African dust. The two sites experience air quality degradation under the influence of African dust plumes, with up to 200 and 300 % increases in coarse particle mass, respectively. Number and volume size distributions provide additional insight on the potential impact of the airborne particles from different sources. The 18-month project allows quantification of the large interannual variability in the frequency and the spatial extent of these aerosol plumes. ADABBOY is the first project to systematically characterize not only the elemental composition of airborne particles as a function of these sources compared with background, mostly marine composition, but also the presence of different types of bioaerosol under the influence of different sources. Bacteria, actinobacteria (both continental and marine) and fungi propagules show seasonal and interannual variability and reveal the presence of very different species and genera related to the different sources. An additional novel contribution of ADABBOY is the determination of the ice-nucleating abilities of particles emitted by the different sources within the tropics, an under-sampled region of the world.
