资源环境科技发展态势分析平台

A three dimensional (3D) variant of the Potential Source Contribution Function (PSCF) model was used in this study, aiming to identify the source areas and altitudinal atmospheric layers associated with PM₁₀ exceedances of the daily EU limit value (>50 μg/m³) during the different seasons in Athens (Greece). The analysis covers the period 1 May 2015 to 31 December 2018, during which direct Saharan dust intrusions from North Africa and especially Libya and Egypt, occurred mainly within the 0-1000 m a.g.l. layer, and were identified as a significant source of PM₁₀ exceedances during all seasons. The maximum probability of dust events was detected in spring, when the dust transport pathways were also vertically extended. Additionally, an increased probability of PM₁₀ exceedances in winter was linked to northerly airflows within both the 0-1000 m a.g.l. and 1000-2000 m a.g.l. layers, indicating regional transport from the Balkans and Northern Greece. To delineate the emission origin of winter PM₁₀ exceedances, the 3D-PSCF model was also applied on concentrations of Black Carbon (BC), its wood burning related fraction (BC_wb) and CO, recognized as markers of incomplete combustion processes. A synoptic analysis showed that the accumulation of local emissions due to stagnant anticyclonic conditions is the primary cause of the PM₁₀, CO, BC and BC_wb episodes in Athens during winter, however 3D-PSCF model also clearly demonstrated supplementary contributions from regional combustion sources located in the Balkans and Northern Greece.