Temporal variations of Eastern Black Sea aerosol

Abstract

In this study, chemical composition of coarse (PM2.5-10) and fine (PM2.5) aerosols and their seasonal characteristics was used to investigate factors affecting seasonal variations in concentrations of species. Concentrations of 17 trace elements and SO42- were determined in coarse and fine aerosol samples collected at a high altitude (1115 m above sea level) site (Torul, 40°32’34”N 39°16’57”E) between March 2011 to November 2012 on the Eastern Black Sea region of Turkey. The samples were analyzed by energy dispersive x-ray fluorescence (EDXRF) using an Oxford ED–2000 Spectrometer. Measured concentrations varied between approximately 0.40 ± 0.7 ng m-3 for As and 2070 ± 1270 ng m-3 for SO42-. Soil-derived elements, Al, Si, K, Ca, Ti, V and Fe, had higher concentrations in the coarse fraction as expected. The results indicated that concentrations of elements showed well-defined seasonal variations. Crustal elements showed higher concentration in summer. Na, which is an element generally associated with sea salt had also higher concentrations in summer season, suggesting a strong crustal contribution to Na concentration at our station. Anthropogenic elements As, Zn, Pb and Cr had comparable concentrations in both seasons. Cu, Ni, and V, had higher concentrations in winter season due to sources close to sampling point. Crustal enrichment factors of Ni, Cu, Cr, As, Pb, Zn and SO42- varied between 12 for Ni and 800 for SO42-. Upper atmospheric flow climatology showed that most frequent flow direction was the sector between West and North, indicating the regions between these wind sectors are the potential source regions for the observed levels of species.