8.2 Aerosols
Aerosols are suspended particles (solid or liquid) in the atmosphere. They affect climate by scattering/absorbing radiation and modifying clouds.
Aerosol Types
Sea Salt
From ocean spray. Hygroscopic, good CCN.
Dust
Mineral particles from deserts. Affects radiation, ice nuclei.
Black Carbon
From incomplete combustion. Absorbs radiation, warms atmosphere.
Sulfate
From SO₂ oxidation. Scatters radiation, cooling effect.
Climate Effects
Direct Effect
Scattering and absorption of radiation. Net cooling ~-0.5 W/m².
Indirect Effect
More CCN → more/smaller cloud droplets → brighter clouds. Uncertain: -0.5 to -1.5 W/m².