Chemical and optical characterization of submicronic aerosol sources

This study analyses the relationship between the scattering properties and the chemical compounds internal mixture of the aerosolsnear Bucharest, Romania. Several cases of local aerosolsinfluenced by heating sources, like wood or fossil fuel, are characterized in order to retrieve the winter period specificity. Correlation between organic and inorganic aerosolscomposition from mass spectrometry measurements made with Compact Time (CT) of Flight AerosolMass Spectrometer (AMS) and scattering coefficient derived from Nephelometermeasurements is highlighted. The scattering coefficient tendency can be assigned to some of the chemical components of the aerosols, exploiting the correlation coefficient with some fragments during the measurements period. High concentrations of organic markers specific for CO2 fragment (m/z 44) indicate the presence of oxygenated organic aerosolswith low volatility. The aerosolsaging process is emphasized by ratio between markers with different degrees of oxidation, as f44 and f43 (high oxidized marker, m/z 44 to total signal and low oxidized marker m/z 43 to total signal). Lower values are characteristic for the beginning of February and higher at the end of February and beginning of March. During winter, several aerosolsources were present, the m/z 57 marker being related to traffic. Strong correlations were revealed between m/z 43, 60 and 73 and the scattering coefficient.