Numerical study of atmospheric dispersion of a substance released from an industrial complex in the southern coast of Korea

Diurnal variations of wind field and pollutant dispersion in a complex terr ain with a shoreline were investigated under the insolation conditions of s ummer and winter. The area is located in the south of the Korean Peninsula and includes a large petrochemical industrial complex. The Regional Atmosph eric Modeling System (RAMS) was used in the simulation study. Initially, ho rizontally homogeneous wind fields were assumed on the basis of sounding da ta at the nearby upper-air station for days with morning wind speeds below 2 m s(-1). On these days, the sea breeze prevailed in summer while the land breeze lasted for a few hours in the morning; the effect of synoptic winds was strong in winter with some inclusion of wind variations owing to the i nteraction between sea and land. The predicted wind direction at the locati on of the weather station captured an important change of the sea/land bree ze of the observed one. In the morning, both in summer and winter, complica ted wind fields with low wind speeds resulted in high pollutant concentrati ons almost all over the area. On the other hand, in the afternoon, the wind field was rather uniform and the terrain effects were not significant even in the mountainous area with the development of a mixing layer. (C) 2001 E lsevier Science Ltd. All rights reserved.