Tropospheric Anthropogenic Aerosols and Climate

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The overall goal of this research program is to characterize the radiative forcings of tropospheric sulfate and carbonaceous aerosols and to quantify the climatic impact of these forcings. To address this goal, a three-dimensional interactive aerosol-climate model based on the Community Climate System Model (CCSM) of the National Center for Atmospheric Research (NCAR) will be developed and improved. Besides the original CCSM, this model includes (1) an aerosol model that describes atmospheric evolution of multiple size sections (modes) of sulfate and carbonaceous aerosols as well as their mixtures influenced by transport, scavenging, and conversions; and (2) a prognostic size-dependent radiative effect of aerosols and associated influence on climate dynamics and physics as well as land surface properties. Modeled results with this interactive model, including tropospheric concentrations and radiative properties of aerosols, are expected to be evaluated using observations and high-resolution regional model results, and then used to quantify the direct and indirect radiative forcings of various modeled aerosol components. The key dynamic and physical processes, and the most significant uncertainties in determining the tropospheric aerosol burden, are to be identified. This will be addressed by launching a large number of sensitivity runs with different model settings, formulas, initial profiles, or emission projections that are based on various pollution control strategies at different geographical locations. Broader Impacts: This project will produce several important byproducts including training a postdoctoral research fellow and providing students as well as fellow researchers an educational and research tool to study aerosol-climate interactions and related issues. The subject treated also is relevant to issues of climate change and will benefit environmental management and policy decision-making.