Evaluation of simulated aerosols and clouds in CAM5 with different representation of aerosol microphysics

 
Poster PDF

Authors

Catherine Chuang — Lawrence Livermore National Laboratory
Arthur Mirin — Lawrence Livermore National Laboratory
Philip Cameron-Smith — Lawrence Livermore National Laboratory
Dan Bergmann — Lawrence Livermore National Laboratory

Category

Aerosol Properties

Description

A sectional aerosol package (Sect) that precisely links precursor gases to aerosol formation and size distribution for Community Atmosphere Model (CAM) 5 has been developed at Lawrence Livermore National Laboratory. This aerosol module integrates the Model of Ozone and Related Tracers (MOZART) gas chemistry with Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) aerosol microphysics and an online biogenic emission system, Model of Emissions of Gases and Aerosols from Nature (MEGAN). Formation of secondary organic aerosols (SOAs) is simulated from 4 anthropogenic and 14 biogenic organic aerosol precursors. One unique aspect of CAM5/Sect is its capability to account for the impacts of interactive chemistry and size-resolved aerosol properties on atmospheric aerosol burdens. In addition to SOAs, other aerosol types simulated include sodium, sulfate, ammonium, nitrate, chloride, dust, primary black carbon, and organic carbon. The prognostic size-resolved aerosol components are subsequently coupled to photolysis, heterogeneous, and aqueous phase chemical reactions as well as cloud nucleation process. The number of constituents carried in CAM5/Sect is 335, as compared to 25 for the default version of CAM5 with the modal aerosol package (CAM5/MAM).

We started with two-degree horizontal resolution and eight size bins (0.02–10 micron in diameter) and are testing the model capability at high resolution for future use during field campaigns. Simulations of CAM5/Sect and initial comparisons of aerosol concentrations and cloud properties to ARM data will be presented. Evaluation of CAM5 applications with different representation of aerosol microphysics will also be addressed.