AERONET Asia-Pacific Economic Cooperation summit Atlantic coastal European region Collection 6.1 DEM MODIS aerosol product PM10 PM2.5 Research & information: general aerosol mass spectrometry aerosol optical depth MODIS atmospheric particle-bound mercury atmospheric particulate matter chemical composition coarse diurnal heavy aerosol loading household dust indoor air pollution meteorological effect modal structure organic aerosol organic and elemental carbon organic nitrogen particle number size distribution particle size characterization phthalic acid esters polycyclic aromatic hydrocarbons primary organic aerosols resuspension