To quantitatively estimate and analyze the contribution of different aerosol types to radiative forcing, we thoroughly investigated their optical and radiative properties using the Aerosol Robotic Network (AERONET) data (2007-2018) over an urban-industrial (Lahore) and coastal (Karachi) cities located in Pakistan. The contribution of inferred aerosol types following the threshold applied for FMF500 versus SSA(440) and EANG(440-870) versus AANG(440-870) were found the highest for pure dust (PUD, 31.90%) followed by polluted continental (POC, 24.77%) types of aerosols, with moderate contribution was recorded for polluted dust (POD, 20.92%), organic carbon dominating (OCD, 11.85%), black carbon dominating (BCD, 8.77%) and the lowest for the non-absorbing (NOA, 1.79%) aerosol type. Seasonally, the mean (+/- SD) aerosol optical thickness at 440 nm (AOT(440)) was found maximum (0.73 +/- 0.36) for PUD type in summer and minimum for BCD (0.25 +/- 0.04) during spring at Karachi. However, the mean (+/- SD) AOT(440) varied from 0.85 +/- 0.25 during summer to 0.57 +/- 0.30 in winter at Lahore, with the highest contributions for POC (29.91%) and BCD (22.58%) and the lowest for NOA (5.85%) type of aerosols. Further, the intensive optical properties showed significant temporal and spectral changes and the complexity of inferred aerosol types over the study sites. The results are well substantiated with the air mass analysis obtained from the concentration weighted trajectory (CWT) model for different aerosol types. The Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model revealed the strong presence of BCD aerosol type led to a surface (BOA) and top of atmosphere (TOA) forcing of -70.12, -99.78 Wm(-2) and -9.60, -19.74 Wm(-2), with an annual heating rate of 2.10 and 2.54 Kday(-1), respectively, at Karachi and Lahore sites.

According to satellite monitoring data (MODIS/Terra), the spatial distribution of the aerosol optical depth (AOD) at a wavelength of 550 nm for the summer smog of 2007 over the North China Plain (NCP) and adjacent areas has been obtained. Areas over which the AOD is higher due to regional anthropogenic contamination sources near Beijing and Shanghai, as well as the smoke haze forming due to agricultural burning (the southwest part of the NCP), have been revealed. The similarity of optical and microphysical characteristics of aerosol in the smoke haze over the NCP and in the Russian territory has been found: (i) the decisive contribution to the optical characteristics of smoke aerosol is made by the fine mode and (ii) the attenuation spectra in the wavelength region 340-1020 nm are approximated (in logarithmic coordinates) by parabolas or fourth degree polynomials. The monitoring data at the AERONET Beijing site show that the single scattering albedo in the summer smog over the NCP is on average less (0.91) than in the smoke haze in the Russian territory (0.95-0.96). The radiative regimes of the atmosphere are significantly different: in the smog, the aerosol radiative forcing efficiency is lower approximately by 30% at the top of the atmosphere and higher by 30% at the bottom of the atmosphere than in the smoke haze.