Development and application of three-dimensional potential source contribution function (3D-PSCF)

A potential source contribution function (PSCF) can indicate the source areas of high air pollutant concentrations using backward trajectories. However, the conventional two-dimensional PSCF (2D-PSCF) cannot consider the emission and transport height of air pollutants. That missing information might be critical because injection height varies depending on the source type, such as with biomass burning. We developed a simple algorithm to account for the height of trajectories with high concentrations and combined it with the conventional PSCF to devise 3D-PSCF. We demonstrate the applicability of the 3D-PSCF by applying it to particulate PAH data collected from September 2006 to August 2007 in Seoul. We found variation in the results from 3D-PSCF with threshold heights from 3,000 to 1,500 m. Applying 2,000 m as the threshold height in the PSCF calculation most clearly determined the possible source areas of air pollutants from biomass fuel burning that were affecting the air quality in Seoul.