Geographical and temporal variations of chemical constituents in winter precipitation collected in the areas along the coast of the sea of Japan

摘要

The geographical and temporal variations of chemical constituents in winter precipitation collected in the areas along the coast of the Sea of Japan (AASJ) were discussed by analyzing the data obtained in the 1st and 2nd National Acid Deposition Survey by Japan Environmental Laboratories Association. In western Tohoku (WT) and Hokuriku (HR) areas in AASJ, in spite of large amounts of precipitation in winter, concentrations of non sea salt (nss-)SO{sub}4{sup}(2-) are not as low as the other areas, and nss-Ca{sup}(2+) in these areas is lower than the other areas. As a result, H{sup}+ concentrations of precipitation in these areas are somewhat higher than other areas. From the temporal analysis of daily sampled data and back trajectory analysis of air mass, it was found that the concentrations of nss-SO{sub}4{sup}(2-), NO{sub}3{sup}-, NH{sub}4{sup}- and nss-Ca{sup}(2+) are correlatively varied when air mass come from the Asian Continent, showing higher concentrations at the western sites in AASJ and depending on the meteorological conditions such as the direction of in flow air mass.