Influence of meteorology on ambient air quality in Morogoro, Tanzania

Abstract

The influence of meteorological parameters on air quality was investigated for a rural background site in Morogoro. Precipitation, temperature, relative humidity and wind speed were measured during wet and dry seasons of 2005 and 2006 period and their relationship with reported mass of particles of aerodynamic diameter smaller than 10 μm (PM10) for the site was assessed. The results show that higher PM10 mass concentrations (45μg/m 3 ) were obtained during the 2005 dry season and the lowest (13 μg/m 3 ) during the 2006 wet season. It is interpreted that reasons for the higher levels of the particulate matter mass in the dry season are due to temperature inversions and absence of rain wash­down. The observed particulate matter levels are also affected by the variations in sources strengths and in meteorological conditions such as mixing height, precipitation, relative humidity, wind speed and direction as supported by air mass trajectories.