Fogwater Chemistry at a Mountainside Forest and the Estimation of the Air Pollutant Deposition via Fog Droplets Based on the Atmospheric Quality at the Mountain Base

Fogwater chemistry has been observed at Mt. Oyama abutting on the Kanto Plain in Japan. Many air pollutants are deposited via fog droplets, and the nitrogen deposition rate via fogwater is at the same level as that via rainwater. The fogwater concentrations depend on the air pollutant concentrations, liquid water content, and the fog base altitude estimated from the meteorological data for the mountain base. The air pollution dominating the concentrations of fogwater components can be estimated from the sulfur dioxide concentration at the base of the mountain. The concentrations of fogwater components were dominated by the absorbing rates of air pollutants into the fog droplets and were not inversely proportional to the LWC. The concentration of fogwater can be estimated approximately from the SO 2 concentration at the mountain base, the fog base altitude, and the LWC measured for the fogwater.