Behavior of secondary inorganic species in gaseous and aerosol phases measured in Fukue Island, Japan, in dust season

The denuder/filter-pack sampling system has been used to simultaneously measure the daily concentrations of inorganic compounds of fine and coarse aerosol and related gases in Fukue Island, Japan, in three springs (March–April of 2000–2002). Gaseous nitric acid concentrations are low, and gas-to-total (gas+aerosol) fractions of nitrate are also low. The gas-to-total fraction of ammonium and the production of non-sea-salt (nss)-sulfate on coarse aerosol increase with dust loading. Total nitrate concentration correlates with both total ammonium concentration and total aerosol nss-sulfate concentration, although these species are differently partitioned among the gas and fine- and coarse-aerosol phases. In some dust events, there is a time lag between an increase in nss-sulfate concentration and an increase in dust loading. Trajectory analysis shows that one of the dust events with a time lag is composed of nss-sulfate from the east affected by volcanic plumes and dust from the northwest passing over the loess areas in the Asian continent.