Haywood, J. M., K. P. Shine, and A. Slingo, 1996: Direct radiative forcing of anthropogenic sulfate and soot aerosol using a flexible radiation code and a GCM. In IRS '96: Current Problems in Atmospheric Radiation, Proceedings of the International Radiation Symposium, Fairbanks, Alaska, 19-24 August 1996. Hampton, Virginia: Deepak Publishing, 324-327.

Abstract: The Edwards and Slingo, 1996, radiation code is used to determine the important features of the radiative forcing due to anthropogenic emissions of sulfate and fossil-fuel soot aerosol. The spectral resolution of the radiation code is flexible allowing a relatively fine spectral resolution in column calculations and a coarser resolution in GCM calculations to reduce computational time. Column calculations are performed for both sulfate and soot aerosol to investigate the sensitivity of the radiative forcing to solar zenith angle, surface reflectance and the vertical position of aerosol and cloud. The GCM calculations use the Hadley Centre Unified Model to quantify the radiative forcing due to sulfate aerosol using the distributions generated for the 'slow oxidation case' of Langner and Rodhe, 1991. In addition, by assuming that anthropogenic concentrations of soot are correlated to those of sulfate, a rough estimate of the radiative forcing due to soot from fossil fuels is obtained. Additional calculations using the GFDL 16-stream line-by-line code of Ramaswamy and Freidenreich, 1991, are performed to assess the accuracy of the radiative forcing calculated in the GCM.