Effect of the weather condition and volcanic gas from Miyake Island on the ionic pollution of rain and fog water at the Akita Hachimantai mountain range

Abstract

Rain and fog samples were collected from the Akita Hachimantai mountain range between June and September, 2000. By classifying the course of transport of the air mass by 72 h back trajectory at the 850 hPa level, when the air masses were transported from the Korean Peninsula or near China, the ion concentrations were shown to be very high by nss-SO₄²⁻. After 8 July, 2000, when a volcano erupted at Miyake Island, a high [nss-SO₄²⁻]/[NO₃⁻] ratio was observed in some samples. It was concluded that the samples had been influenced by volcanic gas from Miyake Island using 72 h back trajectory at the 850 hPa level.