Effect of Low Pressure System Passings Along South Coast of Japan on Chemical Composition of Snow Collected in Joetsu City

Abstract

Precipitation samples (snow) fallen before and after of a strong low pressure passings along south cMoast of Japan were collected at Joetsu city, Niigata, Japan. Dissolved ions such as Na⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, Br^-, NO₃^-, and SO₄^2- and pH value were analyzed. The concentration of nss-SO₄^2-and nss-Ca²⁺ were very low and that of NO₃^- was high before the low pressure passings when the air mass above the Pacific Ocean would be brought to Joetsu city. The concentration of nss-SO₄^2- and nssCa²⁺ increased and that of NO₃^- decreased after the passings when the air mass above the Japan sea would be brought. The pH value was 5.38 and 4.77 before and after passings, respectively. The d ecrease in pH value corresponded to the increase in nss-SO₄^2-