Pacific Northwest National Laboratory, Richland, Washington, USA
Received: 11 Jun 2013 – Discussion started: 12 Jul 2013
Abstract. Estimating anthropogenic aerosol effects on the planetary energy balance through the aerosol influence on clouds using the difference in cloud radiative forcing from simulations with and without anthropogenic emissions produces estimates that are positively biased. A more representative method is suggested using the difference in cloud radiative forcing calculated as a diagnostic with aerosol scattering and absorption neglected. The method also yields an aerosol radiative forcing decomposition that includes a term quantifying the impact of changes in surface albedo. The method requires only two additional diagnostic calculations: the whole-sky and clear-sky top-of-atmosphere radiative flux with aerosol scattering and absorption neglected.
Revised: 09 Sep 2013 – Accepted: 14 Sep 2013 – Published: 09 Oct 2013
Ghan, S. J.: Technical Note: Estimating aerosol effects on cloud radiative forcing, Atmos. Chem. Phys., 13, 9971-9974, doi:10.5194/acp-13-9971-2013, 2013.