HR: 10:50h
AN: A42B-03    [Abstracts]
TI: Sensitivity of aerosol loading and properties to cloudiness
AU: * Iversen, T
EM: trond.iversen@geo.uio.no
AF: University of Oslo, Department of Geosciences P.O.Box 1022, Blindern, Oslo, N-0315 Norway
AU: Seland, O
EM: oyvind.seland@geo.uio.no
AF: University of Oslo, Department of Geosciences P.O.Box 1022, Blindern, Oslo, N-0315 Norway
AU: Kirkevag, A
EM: alf.kirkevag@geo.uio.no
AF: University of Oslo, Department of Geosciences P.O.Box 1022, Blindern, Oslo, N-0315 Norway
AU: Kristjansson, J E
EM: j.e.kristjansson@geo.uio.no
AF: University of Oslo, Department of Geosciences P.O.Box 1022, Blindern, Oslo, N-0315 Norway
AB: Clouds influence aerosols in various ways. Sulfate is swiftly produced in liquid phase provided there is both sulfur dioxide and oxidants available. Nucleation and Aitken mode aerosol particles efficiently grow in size by collision and coagulation with cloud droplets. When precipitation is formed, aerosol and precursor gases may be quickly removed bay rainout. The dynamics associated with clouds in some cases may swiftly mix aerosols deeply into the troposphere. In some cases Aitken-mode particles may be formed in cloud droplets by splitting agglomerates of particulate matter such as black carbon In this presentation we will discuss how global cloudiness may influence the burden, residence time, and spatial distribution of sulfate, black carbon and particulate organic matter. A similar physico-chemical scheme for there compounds has been implemented in three generations of the NCAR community climate model (CCM3, CAM2 and CAM3). The scheme is documented in the literature and is a part of the Aerocom-intercomparison. There are many differences between these models. With respect to aerosols, a major difference is that CAM3 has a considerably higher global cloud volume and more then twice the amount of cloud water than CAM2 and CCM3. Atmospheric simulations have been made with prescribed ocean temperatures. It is slightly surprising to discover that certain aspects of the aerosols are not particularly sensitive to these differences in cloud availability. This sensitivity will be compared to sensitivities with respect to processing in deep convective clouds.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005