Investigating relationships between aerosol and rainwater compositions at different locations in Turkey

Chemical compositions of atmospheric aerosol and rainwater samples collected at four different locations in Turkey were compared to investigate the relationship between aerosol and rainwater compositions. Results showed that aerosol composition could be reflected closely in rainwater composition if below-cloud processes dominate in-cloud processes. This was clearly observed for crustal elements at all stations and for most elements at the urban station. However, at rural stations there were differences in rain and aerosol that were attributed to significant contributions from in-cloud processes. Seasonal patterns observed in aerosol composition showed general agreement with the corresponding temporal variations observed in concentrations of elements in rainwater. These observations suggest that certain features of rainwater composition can be constructed if concentration data are available for aerosol. However, differences in the data observed at the different stations and among various elements or element groups showed that the composition of rainwater constructed from aerosol data can be only a crude effort. Similarities between rain and aerosol compositions were more pronounced at the urban station as compared to the rural stations. Scavenging ratios calculated using paired daily data were variable both among stations and within a single station. Long-term averaged data were found to be more reliable in calculating scavenging ratios of elements and ions at all stations. (C) 2008 Elsevier B.V. All rights reserved.