降水に含まれる無機成分の化学的特徴(第五報)

概要

論文の詳細を見る
The precipitation samples from May 1993 to February 1994in Yonezawa every rainfall and snowfall were analyzed concerning pH value, electric conductivity (EC) and concentrdtion of major ions (Na+, K+, NH4+, Ca2+, Mg2+, Cl-, NO3-, and SO42-). The annual mean pH values of rainfall and snowfall were 4.5 and 4.7 which were 0.1 lower than the data of the last year, respectively. The results of the annual data observed in Yonezawa from May 1989 to February 1994 were as follows : (1) The lowest pH value was 3.60 in rainfall samples and 3.99 in snowfall samples. The highest EC value was 257μS.cm-1 in rainfall samples and 231μS.cm-1 in snowfall samples. (2) The number of precipitation samples having higher ion concentration has been increasing every year. (3) On monthly total concentration of major ions in precipitation, the concentration in winter was higher 4-5 times than the one in summer. This was dependent on the amounts of sea salts transported by winter monsoon from the Sea of Japan. (4) It was confirmed that non-seasalt(nss)-Cl- from HCl contribute to acidifying the precipitation, because the monthly mean [H+] gradually decreased with an increase in the equivalent concentration of {([NO3-] + [nss-SO42-] + [nss-Cl-]) - ([NH4+] + [nss-Ca2+])}
山形大学の論文
1995-01-31