The Attenuation of Solar Radiation in Urban Atmospheres

Abstract

<p> Unsworth and Monteith's (1972) aerosol attenuation coefficient TA was calculated with hourly cloudless data at four North American and four European stations for varying time periods. Monthly and seasonal turbidity trends were examined. Annual cycles were observed with summer maximums and winter minimums. The North American stations were less turbid and had more pronounced trends than the European stations. Both air mass origin and local weather affect the turbidity. Local sources of pollution have a significant effect on turbidity most notably in large urban centres.</p>