6.4 Assessing Impacts of Aerosol Processes on Equilibrium Climate Sensitivity

摘要

We study possible climate impacts of anthropogenic aerosols by modeling their atmospheric life-cycles, and parameterizing their extinction of solar radiation and interactions with clouds. We have developed and implemented such schemes in the global atmospheric climate model CAM3 of the National Centre for Atmospheric Research (NCAR). We present results from CAM-Oslo coupled to a slab ocean. Equilibrium climate response, assuming different aerosol properties, are estimated as the change in equilibrium values of surface air temperature and precipitation due to changed atmospheric content of CO_2 or aerosol production. Feed-back processes with aerosols are discussed, along with effects of an added background cloud droplet number concentration (cdnc), and how CO_2-induced climate change may influence aerosols.