Aerosols are small particles suspended in the atmosphere with a size ranging from 100 nm to a micron and have strong interaction with electromagnetic waves from ultra-violet and visible to infrared wavelengths. CRTM aerosol optical module is based on the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model which simulates major tropospheric aerosol components, including sulfate, dust, black carbon (BC), organic carbon (OC), and sea-salt aerosols. Physical processes in the GOCART model: Emissions of aerosols and their precursors Transport (advection, convection, BL mixing), Chemistry (gas-to-particle conversion), Dry deposition and settling Wet deposition Hygroscopic growth as a function of RH. The concentraions of each type of aerosols are bin-size dependent for sea salt, dust particles, fixed sized black carbon, organic carbon, sulphate aerosols. Here are four major catogories of aerosls. 1 Sulpher:DMS (Dimethyl sulfide), SO2, SO4, MSA (methanesulfonate), 2. Carbon:Hydrophobic BC/OC, hydrophilic BC/OC (water-like);
3.Dust: 8 bins: 0.1-0.18, 0.18-0.3, 0.3-0.6, 0.6-1, 1.0-1.8, 1.8-3.0, 3.0-6.0, 6.0-10.0 micron; 4. Sea-Salt: 4 bins: 0.1-0.5, 0.5-1.5, 1.5-5.0, 5.-10 micron.
