Optical properties of aerosols over urban and desert areas

الملخص EN

The atmosphere aerosols play an important role in the physical processes occur in the atmosphere.

Such as absorption and scattering of solar radiation and formation of cloud and precipitation.

Consequently, aerosols affect the radiation balance and water balance of atmosphere.

Therefore, the study of optical properties of aerosol is very important in many applications such as modeling of solar radiation, cloud modeling and climate modeling.

The aim of this research is to investigate the aerosols optical properties using the Optical Properties Aerosol and Cloud (OPAC) software package.

Three types of aerosols were considered, namely continental, desert, and urban aerosols.

The results indicated that the optical properties of aerosols (extinction, scattering, absorption coefficients; single scattering albedo; asymmetric parameter, and optical depth) in general decreases with increasing wavelengths but they decrease sharply at shorter wavelength and gradually at longer wavelengths.

In addition, the effect of atmospheric windows is evident in the 5-10 μm range of the spectrum.

The results also suggested that desert aerosols are the most effective type followed by urban and continental polluted aerosols.

Change in relative humidity can affect the optical properties of the continental and urban aerosols while the desert aerosols are almost unaffected by the change of relative humidity.