Abstract ATM-9522681 Schlesinger, Michael E. University of Illinois Title: Research on Greenhouse-Gases-Induced Climate Change This project will focus on the following studies: The Last Glacial-Interglacial Cycle. The objective of this research is to simulate and understand the Glacial-Interglacial Cycle. Following his success in simulating glacial onset from 115kya to 105kya, the PI will continue to use his 2-layer atmospheric general circulation/mixed-layer-ocean/ice-sheet/asthenosphere (AO/ISA) model, first to refine the onset-simulation temporally, and second to continue the simulation from 105kya to the present. Estimation of the Climate Sensitivity, T2x. The objective of this research is to obtain the best-possible estimate of the sensitivity of the climate system, T2x. The PI will do this by simulating the geographical distributions of aerosol concentrations, optical depths, radiative forcing and climate for two years following the Pinatubo eruption. He will incorporate into his 24-layer stratospheric/tropospheric GC/PC- aerosol model with his 12-layer ocean GC model. He will perform 5 experiment simulations including the eruption, and 5 control simulations excluding it; the members of each simulation set differing only in their atmospheric initial conditions. In this way the PI will be able to estimate the contribution of natural internal variability to the post-Pinatubo temperature changes. He will compare the simulated and observed post-Pinatubo temperature changes to determine T2x. Anthropogenic Sulphate Aeroqol Induced Climate Change for Integrated Assessments. The objective of this research is to simulate the equilibrium climate change induced individually and collectively by the radiative forcing of 5 regional sources of anthropogenic sulphate aerosols for use by integrated assessment models. For this objective, the PI will perform 6 equilibrium climate-change simulations with his 7-layer tropospheric GC/MLO model. This researc h is important because it seeks to add new knowledge about climate processes with the goal of improvements in climate predictions.
