Evaluation of nucleation algorithms and their impacts on simulated aerosol number and size distributions and cloud properties
In this study, several homogeneous nucleation parameterizations (e.g., binary, ternary, and empirical power-law), and one ion-mediated nucleation parameterization, will be evaluated in the AERO5 aerosol module in the U.S. Environmental Protection Agency (EPA) Model-3 Community Multiscale Air Quality (CMAQ) modeling system. Simulations with these nucleation parameterizations will be conducted for August 2002 over a domain in the southeastern U.S. at a 4-km horizontal resolution. The results will be evaluated against field measurement data from the 2002 Aerosol Nucleation and Real Time Characterization Experiment (ANARChE) in Atlanta, Georgia, as well as additional observations over rural/remote/coastal/marine areas from literatures. Plausible parameterizations identified from regional simulations will be incorporated into the Global-through-Urban Weather Research and Forecasting model with Chemistry (GU-WRF/Chem) to further evaluate their performance on a global scale using published observations under representative atmospheric conditions. The impacts of different nucleation algorithms on simulated aerosol number concentrations, aerosol size distribution, and cloud properties will be examined.