HR: 14:40h
AN: A53F-05    [Abstracts]
TI: Effect of chemistry-aerosol-climate coupling on global predictions of future climate and future levels of tropospheric ozone and aerosols
AU: * Liao, H
EM: hongliao@mail.iap.ac.cn
AF: Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
AU: Chen, W
EM: annechen@caltech.edu
AF: Department of Environmental Science and Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, United States
AU: Seinfeld, J
EM: seinfeld@caltech.edu
AF: Departments of Chemical Engineering and Environmental Science and Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, United States
AB: Radiative forcing from changing aerosols and tropospheric ozone has the potential to modify climate effects of greenhouse gases, especially regionally. Ozone and aerosols also interact tightly through tropospheric chemical processes, which themselves will be affected by future climate change. In this study we investigate the extent to which chemistry-aerosol-climate feedbacks affect the ultimate levels of year 2100 ozone and aerosols as well as the climate response to changes in long-lived greenhouse gases, tropospheric ozone, and aerosols over 2000- 2100. We simulate tropospheric ozone-NOx-hydrocarbon chemistry and sulfate, nitrate, ammonium, black carbon, primary organic carbon, and secondary organic carbon aerosols online in the Goddard Institute for Space Studies (GISS) general circulation model II'. Year 2100 CO2 concentration as well as the anthropogenic emissions of ozone precursors and aerosols/aerosol precursors are based on IPCC scenario A2. Results indicate that chemistry-aerosol-climate coupling is influential on predicted future ozone and aerosols and consequently on simulated year 2100 climate. For example, as compared to year 2100 climate simulated using offline ozone and aerosol fields calculated based on present-day climate and year 2100 emissions (a commonly used approach in previous studies), predicted year 2100 surface-layer temperatures in the fully coupled simulation are higher over populated areas as a result of regionally higher ozone and aerosol (especially BC) concentrations; changes in temperature there relative to year 2000 are 10-30% higher in the coupled climate simulation if aerosols are internally mixed. Sensitivity studies are performed to identify some key coupling processes in predicting future ozone, aerosols, and climate.
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 1626 Global climate models (3337, 4928)
DE: 1630 Impacts of global change (1225)
DE: 3337 Global climate models (1626, 4928)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting