Analysis of Four-Year Results of Acid Precipitation Based on a Wet-Only Sampling Network in Japan

抄録

Precipitation chemistry in Japan was discussed based on a wet-only event-basis dataset from five sites from April 1984 to March 1988. The annual average pH at each site ranged from pH4.5 to 5.1. Non-seasalt (nss-) sulfate and nitrate concentrations ranged from 30 to 63μmol/L and from 19 to 79μmol/L, respectively. The pH was higher for the concentration levels of nss-sulfate and nitrate. This was attributable to the probable neutralization of the input acidity by additonal alkaline species, gaseous ammonia and particulate calcium species. This was discussed in terms of pH and pAi defined as -log ([nss-SO4^2-]+[NO3^-]).