A new statistical approach to improve the satellite based estimation of the radiative forcing by aerosol-cloud interactions.

In a previous, study of Quaas et al. (2008) the radiative forcing by anthropogenic aerosol due to aerosol-cloud interactions, RF_aci, was obtained by a statistical analysis of satellite retrievals using a multilinear regression. Here we employ a new statistical approach to obtain the six fitting parameters, determined using a non-linear statistical approach to obtain the six fitting parameters, for the relationship between planetary albedo and cloud properties and, further, the relationship of the cloud properties and aerosol optical depth. The statistical approach is compared to the results from radiative transfer simulations over three different regions and for different seasons. We find that the results of the new approach agree well with the simulated results over both land and ocean. The new statistical approach increases the correlation coefficient of the fitted to the satellite-retrieved albedo by 21%-23% and decreases the error, compared to the previous approach. [ABSTRACT FROM AUTHOR]