A preliminary investigation of winter air pollution potential at fort simpson, northwest territories

Abstract

Abstract Based on radio‐sonde data collected during nine consecutive days in February 1974, an examination was made of the daytime variation of the winter mixing depth and air pollution potential in the Fort Simpson area of the Mackenzie Valley. Under anti‐cyclonic weather conditions, mixing depths were generally low (< 100 m) or non‐existent. The generation of a mixed layer was found to be primarily associated with extensive low‐ to mid‐level cloud cover and precipitation. During this period of investigation, ventilation coefficients were extremely low. This suggests that the area has a great risk of high pollution potential in winter.