Wednesday, 16 January 2002: 3:30 PM
Ensemble climate simulations including natural and anthropogenic forcings
We present results from a series of ensemble integrations of a coupled atmosphere-ocean model for the period 1865-2000. Each ensemble consists of three integrations with initial conditions chosen from different junctures of a long control run. The first ensemble includes time-varying forcing from greenhouse gases only. In the remaining three ensembles, forcings from anthropogenic sulfate aerosols, solar variability, and volcanic aerosols in the stratosphere are added progressively, such that the fourth ensemble utilizes all four of these forcings. The effects of anthropogenic sulfate aerosols are represented by changes in surface albedo, and the effects of volcanic aerosols are represented by latitude-dependent perturbations in incident solar radiation. Temporal variations in global and local temperature, ocean heat content, and other climatic quantities from these four ensembles are compared with observed variations.