Increase of Pollutants in Radiation Fog by Fumigation at Takanosu Basin in Northern Japan

抄録

When an inversion layer forms, particulate matter (PM) stagnates in the upper part of the inversion layer. The PM falls to the ground as an inversion layer collapses. This phenomenon generally called fumigation. We sampled radiation fog by constant volume (50 mL) continuously from occurrence to disappearance of radiation fog at Takanosu Basin to clarify the pollution mechanism of radiation fog by fumigation. Our results show that the absolute equivalent of pollutants in fog water such as (NH₄)₂SO₄ and NaCl for eight events increased during the early morning, immediately before the disappearance of radiation fog. Using the series sampling by constant volume of the radiation fog, it was clarified that the increase in pollutant of air by fumigation results in the increase of pollutant in fog droplets.