Field survey of trans-boundary air pollution with high time resolution at coastal sites on the Sea of Japan during winter in Japan

An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO2(g) and HNO3(g) were well correlated, whereas the NH3(g) concentration variation had no correlation with those of SO2(g) and HNO3(g). The NH4 (+) (p)/non-sea-salt- (nss-)SO4 (2) (p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca2+ for survey period were observed. Backward trajectories analyses for the highest nss-Ca2+ concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO3][NH3] and the calculated values.