Identification of source regions of PM_(10) with backward trajectory-based statistical models during PM_(10) episodes

摘要

This study applies backward trajectory-based statistical techniques, residence time, conditional probability and emission attraction to evaluate potential source regions of PM_(10) over a coastal region. PM_(10) episodes were selected by principal component analysis for 1998-2005 over the Kaoping air quality basin. Residence time was applied to identify potential regions in which air parcels would remain over their 6-and 12-h trajectories. Emission attraction and conditional probability were used to analyze contribution ratios of distinct emission sources to air quality stations. The PM_(10) episodes screen 175 days (6 % of total days) and 35.9 % of total station numbers. Residence time and emission attraction clearly identified potential areas in which backward trajectories remained during PM_(10) episodes and high PM_(10) events. Emission attraction evaluated relative contributions of various sources (stationary, line, and area) from specific jurisdictions, and provided information on specific sources for high-priority PM_(10) emissions reduction. The conditional probabilities of emission attraction during high PM_(10) events show that high values concentrated near stationary and area sources in the city of Kaohsiung.