Concentration and Behavior of Particulate Chloride in the Surface Air at Tsukuba, Japan

Abstract

   Results of study on the chloride concentration in the surface air at Tsukuba Science City, Japan, are here reported. The chloride concentration in the airborne particles was high in the winter time, ranging from 0.2 to 16 μg m^-3. In the other seasons, it ranged from 0.2 to 3 μg m^-3 with an average value of 1.2 μg m^-3. The size distribution of chloride particles revealed that in the winter time, chloride is much concentrated in small particles. The high concentration of chloride in winter also coincided with a day of low wind speed with a near the surface inversion layer. A good correlation was found between the concentration of chloride and the total carbon in airborne dust, whereas no relation was found between sodium and chloride. It was concluded that the high concentration of chloride in the surface air in winter was due to the combined effect of local pollution originating from the burning of agricultural waste and the prevailing near surface inversion layer.