Chemical Properties of Atmospheric Aerosols at Kofu, Yamanashi

Abstract

To investigate the aerosol chemistry in Yamanashi Prefecture, observations of the aerosols and their precursor gases were conducted over a three-year period at a residential site close to central Kofu. When compared with the results from other residential areas around Yamanashi Prefecture, ionic species, especially NO₃^- and NH₄⁺, showed lower concentrations, but the carbonaceous species were relatively enriched in the PM₂ at Kofu. Organic matters, soil/mineral components, and nss-SO₄^2- were the main components of the PM₁₀. The mass ratio of PM₂/PM₁₀ was 63.6% on average. The most important contributor to the PM₂ mass was organic matters with high concentrations in winter. They would be mainly derived from vehicle exhausts and biomass burning, but photochemical productions would also be important in summer. Secondly, nss-SO₄^2- had a large contribution to the PM₂ mass with high concentrations in summer due to photochemical productions. Soil/mineral components were the most important for the PM_10–2 mass and increased in spring due to Kosa events. The second most important component of the PM_10–2 was organic matters from biomass burning and plant debris. Except for nss-Ca²⁺and NO₃^-, no effect of long-range transports from the Asian continent on the concentrations was found in the chemical components of the aerosols at Kofu.