MAJOR ION COMPOSITION OF WET AND DRY DEPOSITION IN THE EASTERN MEDITERRANEAN BASIN

Major ions were analysed in wet and dry deposition samples collected f or 1 year (1992), using daily and weekly sampling periods at the Easte rn Mediterranean coast of Turkey. The dry deposition fluxes of marine and crustal ions were found to be higher than their corresponding wet deposition. However, wet deposition fluxes of ions with anthropogenic sources, such as SO4(2-) and NO3- were found to be higher than their d ry deposition rates. The annual average pH of the precipitation was 5. 17, with high variability in the observed values due to different sour ce regions. High concentrations of SO4(2-) and NO3- measured in sample s with high pH indicated extensive neutralization of acidity by alkali ne species. Results suggest that more than 70% of the acidity has been neutralized by CaCO3 which originate both from airborne local soil an d dust transported from North Africa.