Several regional statistical ensembles of tropospheric (0-12 km) aerosol optical properties (extinction - AEC, scattering - ASC, and asymmetry parameter - AP) have been modeled based on up-to-date experimental data. The covariance matrices of optical parameters for continental and marine ensembles have been calculated. The spectral correlation in molecular absorption bands: O2 (0.76 µm), CO2 (1.61 and 2.06 µm) between AEC, ASC, and AP has been studied. These bands are planned to be used in OCO (Orbital Carbon Observatory) Project for determination of CO2 total content with high accuracy. It is shown that a significant correlation (0.7-1.0) takes place between AEC and ASC in all channels. The correlation between AEC and PA is lower (0.05-0.55). The optimal and Angstrom parameterization methods were applied to spectral approximation of AEC, ASC, and PA. It has been shown that the mean error in case of the optimal parameterization totals 0.02-1.5%, in case of the Angstrom parameterization it was 1.2-9.9% for continental and marine aerosol models.