Influences of natural and anthropogenic particles on ambient particulate air quality during typhoon season: From Bashi Channel to Kaoping River Valley.

Aeolian dust episode (ADE) is an emerging disaster occurred from the bare lands of the Kaoping River Valley in southern Taiwan because of typhoons. Four manual sampling sites located along the Kaoping River Valley conducted to collect PM₁₀ (aerodynamic diameter ≤ 10 μm) with high‐volume samplers during the ADE occurred by Typhoon Doksuri, and on regular days. Mass percentages of sea‐salt particles (SSs) in PM₁₀ accounted for 5.47–8.91% on regular days and 11.66–14.05% in phase II. Average mass percentage of Ca²⁺ in phase I increased twice than those on regular days. Cl⁻ deficit percentages were much lower during the ADE (7.37–14.13%) than on regular days (31.69–42.78%), indicating acidic particles mainly produced by chemical reactions of acidic aerosols with aeolian dust and SSs. Even alkaline aeolian dust is a dominant source of the ADE, the atmospheric particles are attributable to acidic particles in the air. Hence, anthropogenic sources play a key role for the worst air quality during typhoon season. [ABSTRACT FROM AUTHOR]