Influence of the growth mechanism of snow particles on their chemical composition

Case studies of chemical analysis of solid precipitation were made at sites on the outskirts and central part of Sapporo City, Japan to investigate the difference in precipitation chemistry owing to the mechanism by which snow particles grow, i.e. by vapor deposition or by riming. Even in vapor depositional growth, the samples were found to be acidic. NO3− and nss-Cl− contributed to the acidification. In the samples of riming growth, the nss-SO42− concentration was considerably high. Snow samples from the site in the central city area were less acidic due to the higher concentration of nss-Ca2+ in the early period of snowfalls.