Radiative Forcing of Urban Aerosols

In this paper, the optical depths, scattering coefficient, absorption coefficient, extinction coefficient and single scattering albedo were modeled using Optical Properties of Aerosols and Clouds (OPAC) by slightly altering the number densities of water soluble at spectral range of 0.25 – 1.00 m for eight different relative humidities (RHs) (0, 50, 70, 80, 90, 95, 98 and 99 %). The data was used to calculate the radiative forcing (RF). The RF was observed to decrease at all RHs given rise to negative RF when compared, as we moved from the first model to the fifth model reflecting the dominance of cooling effect. The scattering coefficient as well as the extinction coefficients and single scattering albedo increases with RHs attributing to a more scattering aerosol. The regression analysis of the Ångström exponents and curvatures which helps in determining the sizes of atmospheric particles was done using SPSS 16.0 software. The analysis reveals that fine mode particles are dominant.