Derivation of aerosol loading from visibility range in Penang Island using atmospheric model

Abstract

Atmospheric aerosol has influenced many atmospheric processes including cloud formation, visibility variation and solar radiation transfer. Atmospheric aerosol plays as an important indicator of visibility distance range because it will obscure the objects that can be seen. Visibility degradation has become an environmental topic of community concern in most urban areas because of low visibility range will lead to the deterioration of air quality. In this study, the atmospheric aerosol loading from the image was retrieved by using urban and maritime with visibility range at the distance of 10 km up to 50 km which are later converted into (%) reflectance. Later the works is established the relationship between aerosol loading and visibility was produced using urban and maritime models. To accommodate with the intention research works, Penang Island has been chosen. This is because of the strategic location of Penang Island which located close to the sea and recognized as one of main urbanized city in Malaysia. Results were indicated that visibility was inversely correlated with aerosol loading, the farthest the visibility range, the lower the aerosol loading. Result also showed that the urban aerosol loading estimated is higher than maritime aerosol. This may influence by meteorological factor such as the higher temperatures in urban could lead to higher rate of smog formation. Lower wind speeds will contribute which it may tend to keep pollutants concentrated over urban areas. Atmospheric urban model can derive the estimated minimum aerosol loading (12.1%) when the visibility range is about 30 km can be used to determine the minimum.