Characteristics of Time Variations of PM₁₀Concentrations in Busan and Interpreting Its Generation Mechanism Using Meteorological Variables

Abstract

In an effort to interpret the characteristics of fine particle concentrations in Busan, time variations of hourly monitored concentrations <TEX>$PM_{10}$</TEX> (Particulate Matter with aerodynamic Diameter <TEX>${\le}10\;{\mu}m$</TEX>) in Busan are analyzed for the period from 2000 to 2005. The characteristics of aerosol second generation formation process is also interpreted qualitatively, by using the statistical analysis of the meteorological variables including temperature, wind speed, and relative humidity. The result shows some significant annual, seasonal, weekly and diurnal variations of <TEX>$PM_{10}$</TEX> concentrations. In particular, seasonal(i.e., spring) variations are governed by frequency of yellow sand events even for the non-yellow sand cases where yellow-sand days are eliminated in our analysis. However, in seasonal variation, summer season predominate lower <TEX>$PM_{10}$</TEX> concentrations due to the frequent precipitation, and weekly and diurnal variations are both found to be reflecting the emission rate from traffic amount. Correlation coefficients between <TEX>$PM_{10}$</TEX> concentration and meterological variables for non-yellow sand days show overall negative correlation with visibility, wind speed, cloud amounts, and relative humidity. However for non-precipitation days, during non-yellow sand period positive correlation are found clearly with relative humidity, suggesting the importance of secondary aerosol formation in Busan that can be achieved by both homogeneous aerosol formation and heterogeneous transformations resulting from hygroscopic aerosol characteristics.