HR: 17:45h
AN: A32D-08    [PDF]
TI: Global Estimates of the Influence of Sulphate and Carbonaceous Aerosols on Radiation and Clouds in an AGCM
AU: * Iversen, T
EM: trond.iversen@geo.uio.no
AF: Department of Geosciences, Meteorology and Oceanography Section, University of Oslo, P.O. Box 1022, Blindern, Oslo, N-0315 Norway
AU: Kristjansson, J
EM: j.e.kristjansson@geo.uio.no
AF: Department of Geosciences, Meteorology and Oceanography Section, University of Oslo, P.O. Box 1022, Blindern, Oslo, N-0315 Norway
AU: Kirkevag, A
EM: alf.kirkevag@geo.uio.no
AF: Department of Geosciences, Meteorology and Oceanography Section, University of Oslo, P.O. Box 1022, Blindern, Oslo, N-0315 Norway
AU: Seland, O
EM: oyvind.seland@geo.uio.no
AF: Department of Geosciences, Meteorology and Oceanography Section, University of Oslo, P.O. Box 1022, Blindern, Oslo, N-0315 Norway
AB: A version of NCAR CCM3.2 extended with the Rasch and Kristjansson (1998) cloud scheme and a life-cycle scheme for sulphate and carbonaceous aerosols (Iversen and Seland, 2002), is run as an AGCM (CCM-Oslo). The present aerosol treatment starts out from prescribed properties of sea-salt and continental particles (background), whilst sulphate, black carbon and primary organic carbon are calculated in prognostic mode from emissions used in IPCC-TAR. Produced particles are allocated according to production mechanisms. These include oxidation followed by nucleation or condensation, coagulation in clear and cloudy air, and oxidation in cloud droplets. The degree of internal vs. external mixing and the turnover from hydro-phobic to -philic BC are thus determined by processes. A special treatment of vertical transport and scavenging during deep moist convection has been designed. Interpolation between tabulated discrete values of optical and water-activity parameters enables estimates of interactions between the aerosol particles, clouds and radiation (Kirkevag and Iversen, 2002; Kristjansson, 2002). The Tables have recently been updated for a more realistic background aerosol according to observations, and with OC. Results provided for the ongoing AEROCOM intercomparison project (Schultz and Kinne) will be discussed.
UR: http://nansen.ipsl.jussieu.fr/AEROCOM/aerocomhome.html
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0368 Troposphere--constituent transport and chemistry
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting