AQUEOUS GREENHOUSE SPECIES IN CLOUDS, FOGS, AND AEROSOLS

Greenhouse effects from fossil fuel combustion leading to increased co ncentrations of primary and secondary greenhouse gases (e.g., CO2, ozo ne, etc.) have received considerable attention. More recently, it has been suggested that clouds, aerosols, and fogs can play opposing roles in climate forcing by scattering or absorbing incoming solar radiatio n as well as by absorbing long-wave radiation as it escapes into space . The total effect on the radiation balance depends on the relative ma gnitude of these opposing forces, which in turn will depend on the com position of the aqueous phase. This work describes the measurement of water-soluble infrared absorbers which can contribute to the long-wave radiative forcing of clouds, fogs, and aerosols. Aqueous species whic h have been characterized include sulfate, nitrate, formate, acetate, oxalate, phenol, p-nitrophenol, ammonium, bicarbonate, formaldehyde, m ethanol, and ethanol. Infrared absorption band positions and band stre ngths have been determined, and their relative effects on radiative fo rcing are discussed.