ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-6939-2008 Global simulations of aerosol processing in clouds Hoose C. 1 4 Lohmann U. 1 Bennartz R. 2 Croft B. 3 Lesins G. 3 ETH Zurich, Institute for Atmospheric and Climate Science, Zurich, Switzerland Atmospheric and Oceanic Sciences, University of Wisconsin, Madison, WI, USA Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Canada now at: Department of Geosciences, University of Oslo, Norway 02 12 2008 8 23 6939 6963 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/8/6939/2008/acp-8-6939-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/6939/2008/acp-8-6939-2008.pdf

An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

 References Abdul-Razzak, H. and Ghan, S J.: A parameterization of aerosol activation 2. Multiple aerosol types, J. Geophys. Res., 105, 6837–6844, 2000. Adler, R., Huffman, G., Chang, A., Ferraro, R., Xie, P., Janowiak, J., Rudolf, B., Schneider, U., Curtis, S., Bolvin, D., Gruber, A., Susskind, J., Arkin, P., and Nelkin, E.: The version-2 global precipitation climatology project (GPCP) monthly precipitation analysis (1979–present), J. Hydrometeorol., 4, 1147–1167, 2003. Baltensperger, U., Schwikowski, M., Jost, D T., Nyeki, S., Gäggeler, H W., and Poulida, O.: Scavenging of atmospheric constituents in mixed phase clouds at the high-alpine site Jungfraujoch Part I: Basic concept and aerosol scavenging by clouds, Atmos. Environ., 32, 3975–3983, 1998. Barth, M C., Rasch, P J., Kiehl, J T., Benkovitz, C M., and Schwartz, S E.: Sulfur chemistry in the National Center for Atmospheric Research Community Climate Model: Description, evaluation, features, and sensitivity to aqueous chemistry, J. Geophys. Res., 105, 1387–1416, 2000. Beheng, K D.: A parameterization of warm cloud microphysical conversion processes, Atmos. Res., 33, 193–206, 1994. Bennartz, R.: Global assessment of marine boundary layer cloud droplet number concentration from satellite, J. Geophys. Res., 112, D02201, doi:10.1029/2006JD007547, 2007. Bower, K., Choularton, T., Gallagher, M., Colvile, R., Wells, M., Beswick, K., Wiedensohler, A., Hansson, H., Svenningsson, B., Swietlicki, E., Wendisch, M., Berner, A., Kruisz, C., Laj, P., Facchini, M., Fuzzi, S., Bizjak, M., Dollard, G., Jones, B., Acker, K., Wieprecht, W., Preiss, M., Sutton, M., Hargreaves, K., Storeton-West, R., Cape, J., and Arends, B.: Observations and modelling of the processing of aerosol by a hill cap cloud, Atmos. Environ., 31, 2527–2543, 1997. Croft, B., Lohmann, U., Stier, P., Wurzler, S., Martin, R. V., Feichter, J., and Ferrachat, S.: Aerosol Size-Dependent Below-Cloud Scavenging by Rain and Snow in the ECHAM5-HAM GCM, in preparation, 2008a. Croft, B., Lohmann, U., Martin, R. V., Stier, P., Wurzler, S., Feichter, J., Heikkilä, U., and Ferrachat, S.: Microphysically-dependent in-cloud scavenging in warm, mixed and ice clouds in the Global Climate Model ECHAM5-HAM, in preparation, 2008b. Easter, R C., Ghan, S J., Zhang, Y., Saylor, R D., Chapman, E G., Laulainen, N S., Abdul-Razzak, H., Leung, L R., Bian, X., and Zaveri, R A.: MIRAGE: Model description and evaluation of aerosols and trace gases, J. Geophys. Res., 109, D20210, doi:10.1029/2004JD004571, 2004. Flossmann, A., Hall, W D., and Pruppacher, H.: A Theoretical Study of the Wet Removal of Atmospheric Pollutants. Part I: The redistribution of aerosol-particles captured through nucleation and impaction scavenging by growing cloud drops, J. Atmos. Sci., 42, 583–606, 1985. Ghan, S J., Chuang, C C., and Penner, J E.: A parameterization of cloud droplet nucleation part I: single aerosol type, Atmos. Res., 30, 198–221, 1993. Ghan, S J. and Schwartz, S E.: Aerosol properties and processes: A path from field and laboratory measurements to global climate models, B. Am. Meteorolog. Soc., 88, 1057–1083, 1993. Gillani, N V., Schwartz, S E., Leaitch, W R., Strapp, J W., and Isaac, G A.: Field observations in continental stratiform clouds: Partitioning of cloud particles between droplets and unactivated interstitial aerosols, J. Geophys. Res., 100, 18 687–18 706, 1995. Greenwald, T J., Stephens, G L., Vonder Haar, T H., and Jackson, D L.: A physical retrieval of cloud liquid water over the global oceans using Special Sensor Microwave/Imager (SSM/I) observations, J. Geophys. Res., 98, 18 471–18 488, 1993. Guelle, W., Schulz, M., Balkanski, Y., and Dentener, F.: Influence of the source formulation on modeling the atmospheric global distribution of sea salt aerosol, J. Geophys. Res., 106, 27 509–27 524, 2001. Han, Q., Rossow, W B., Chou, J., and Welch, R M.: Global variation of column droplet concentration in low-level clouds, Geophys. Res. Lett., 25, 1419–1422, 1998. Heintzenberg, J., Covert, D C., and van Dingenen, R.: Size distributions and chemical composition of marine aerosols: a compilation and review, Tellus, 52B, 1104–1122, 2000. Henning, S., Bojinski, S., Diehl, K., Ghan, S., Nyeki, S., Weingartner, E., Wurzler, S., and Baltensperger, U.: Aerosol partitioning in natural mixed-phase clouds, Geophys. Res. Lett., 31, L06101, doi:10.1029/2003GL019025, 2004. Holben, B., Eck, T., Slutsker, I., Tanré, D., Buis, J., Setzer, A., Vermote, E., Reagan, J., Kaufman, Y J., Nakajima, T., Lavenu, F., Jankowiak, I., and Smirnov, A.: AERONET – A Federated Instrument Network and Data Archive for Aerosol Characterization, Remote Sens. Environ., 66, 1–16, 1998. Hoose, C., Lohmann, U., Stier, P., Verheggen, B., and Weingartner, E.: Aerosol Processing in Mixed-Phase Clouds in ECHAM5-HAM: Model Description and Comparison to Observations, J. Geophys. Res., 113, D07210, doi:10.1029/2007JD009251, 2008. Hoppel, W A., Frick, G M., and Larson, R E.: Effect of nonprecipitating clouds on the aerosol size distribution in the marine boundary layer, Geophys. Res. Lett., 13, 125–128, 1986. Hoppel, W A., Fitzgerald, J., W., Frick, G M., Larson, R E., and Mack, E J.: Aerosol Size distributions and optical properties found in the marine boundary layer over the Atlantic Ocean, J. Geophys. Res., 95, 3659–3686, 1990. Ivanova, I T. and Leighton, H G.: Aerosol-cloud interactions in a mesoscale model. Part I: Sensitivity to activation and collision-coalescence, J. Atmos. Sci., 65, 289–308, 2008. Jones, A., Roberts, D L., Woodage, M J., and Johnson, C E.: Indirect sulphate aerosol forcing in a climate model with an interactive sulphur cycle, J. Geophys. Res., 106, 20 293–20 310, 2001. Kärcher, B. and Lohmann, U.: A parameterization of cirrus cloud formation: Homogeneous freezing including effects of aerosol size, J. Geophys. Res., 107(D23), 4698, doi:10.1029/2001JD001429, 2002. Khairoutdinov, M. and Kogan, Y.: A New Cloud Physics Parameterization in a Large-Eddy Simulation Model of Marine Stratocumulus, Mon. Weather Rev., 128, 229–243, 2000. Kiehl, J T. and Trenberth, K.: Earth's annual global mean energy budget, Bull. Amer. Meteorol. Soc., 78, 197–208, 1997. Kinne, S.: Remote sensing data combinations – superior global maps for aerosol optical depth, in: Satellite Aerosol Remote Sensing Over Land, edited by: Kokhanovsky, A. A. and De Leeuw, G., Springer, in press, 2008. Koch, D., Schmidt, G A., and Field, C V.: Sulfur, sea salt, and radionuclide aerosols in GISS ModelE, J. Geophys. Res., 111, D06206, doi:10.1029/2004JD005550, 2006. Lelieveld, J., Crutzen, P J., and Rodhe, H.: Zonal average cloud characteristics for global atmospheric chemistry modelling, Tech. Rep. CM 76, MISU, Department of Meteorology, Stockholm University, Stockholm, 54 pp., 1989. Lin, B. and Rossow, W B.: Seasonal variation of liquid and ice water path in nonprecipitating clouds over oceans, J. Climate, 9, 2890–2902, 1996. Lin, H. and Leaitch, R.: Development of an in-cloud aerosol activation parameterization for climate modelling, in: Proc. WMO Workshop on Measurements of Cloud Properties for Forecasts of Weather, Air Quality and Climate, Mexico City, 1997. Lohmann, U.: Global anthropogenic aerosol effects on convective clouds in ECHAM5-HAM, Atmos. Chem. Phys., 8, 2115–2131, 2008. Lohmann, U. and Roeckner, E.: Design and performance of a new cloud microphysics scheme developed for the ECHAM general circulation model, Clim. Dynam., 12, 557–572, 1996. Lohmann, U., Feichter, J., Chuang, C C., and Penner, J E.: Prediction of the number of cloud droplets in the ECHAM GCM, J. Geophys. Res., 104, 9169–9198, 1999. Lohmann, U., Stier, P., Hoose, C., Ferrachat, S., Kloster, S., Roeckner, E., and Zhang, J.: Cloud microphysics and aerosol indirect effects in the global climate model ECHAM5-HAM, Atmos. Chem. Phys., 7, 3425–3446, 2007. Ma, X. and von Salzen, K.: Dynamics of the sulphate aerosol size distribution on a global scale, J. Geophys. Res., 111, D08206, doi:10.1029/2005JD006620, 2006. O'Dell, C W., Wentz, F., and Bennartz, R.: Cloud Liquid Water Path from Satellite-Based Passive Microwave Observations: A New Climatology over the Global Oceans, J. Climate, 21, 1721–1739, 2008. Posselt, R. and Lohmann, U.: Introduction of prognostic rain in ECHAM5: design and single column model simulations, Atmos. Chem. Phys., 8, 2949–2963, 2008. Pruppacher, H R. and Jaenicke, R.: The processing of water vapor and aerosols by atmospheric clouds, a global estimate, Atmos. Res., 38, 283–295, 1995. Pruppacher, H R. and Klett, J D.: Microphysics of Clouds and Precipitation, Atmospheric and Oceanographic Sciences Library, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1997. Roelofs, G. J., Stier, P., Feichter, J., Vignati, E., and Wilson, J.: Aerosol activation and cloud processing in the global aerosol-climate model ECHAM5-HAM, Atmos. Chem. Phys., 6, 2389–2399, 2006. Smirnov, A., Holben, B N., Eck, T F., Dubovik, O., and Slutsker, I.: Cloud-Screening and Quality Control Algorithms for the AERONET Database, Remote Sens. Environ., 73, 337–349, 2000. Stier, P., Feichter, J., Kinne, S., Kloster, S., Vignati, E., Wilson, J., Ganzeveld, L., Tegen, I., Werner, M., Balkanski, Y., Schulz, M., Boucher, O., Minikin, A., and Petzold, A.: The aerosol-climate model ECHAM5-HAM, Atmos. Chem. Phys., 5, 1125–1156, 2005. Storelvmo, T., Kristjánsson, J E., and Lohmann, U.: Aerosol influence on mixed-phase clouds in CAM-Oslo, J. Atmos. Sci., 65, 3214, doi:10.1175/2008JAS2430.1, 2008. Sundqvist, H., Berge, E., and Kristjánsson, J E.: Condensation and Cloud Parameterization Studies with a Mesoscale Numerical Weather Prediction Model, Mon. Weather Rev., 117, 1641–1657, 1989. Textor, C., Schulz, M., Guibert, S., Kinne, S., Balkanski, Y., Bauer, S., Berntsen, T., Berglen, T., Boucher, O., Chin, M., Dentener, F., Diehl, T., Easter, R., Feichter, H., Fillmore, D., Ghan, S., Ginoux, P., Gong, S., Grini, A., Hendricks, J., Horowitz, L., Huang, P., Isaksen, I., Iversen, I., Kloster, S., Koch, D., Kirkevåg, A., Kristjansson, J. E., Krol, M., Lauer, A., Lamarque, J. F., Liu, X., Montanaro, V., Myhre, G., Penner, J., Pitari, G., Reddy, S., Seland, Ø., Stier, P., Takemura, T., and Tie, X.: Analysis and quantification of the diversities of aerosol life cycles within AeroCom, Atmos. Chem. Phys., 6, 1777–1813, 2006. Timmreck, C. and Schulz, M.: Significant dust simulation differences in nudged and climatological operation mode of the AGCM ECHAM, J. Geophys. Res., 109, D13202, doi:10.1029/2003JD004381, 2004. Tompkins, A M.: A prognostic parameterization for the subgrid-scale variability of water vapor and clouds in large-scale models and its use to diagnose cloud cover, J. Atmos. Sci., 59, 1917–1942, 2002. Tost, H., Jöckel, P., and Lelieveld, J.: Influence of different convection parameterisations in a GCM, Atmos. Chem. Phys., 6, 5475–5493, 2006. Tost, H., Jöckel, P., Kerkweg, A., Pozzer, A., Sander, R., and Lelieveld, J.: Global cloud and precipitation chemistry and wet deposition: tropospheric model simulations with ECHAM5/MESSy1, Atmos. Chem. Phys., 7, 2733–2757, 2007. Verheggen, B., Cozic, J., Weingartner, E., Bower, K., Mertes, S., Connolly, P., Gallagher, M., Flynn, M., Choularton, T., and Baltensperger, U.: Aerosol partitioning between the interstitial and the condensed phase in mixed-phase clouds, J. Geophys. Res., 112, D23202, doi:10.1029/2007JD008714, 2007. Weng, F., Grody, N C., Ferraro, R., Basist, A., and Forsyth, D.: Cloud liquid water climatology from the Special Sensor Microwave/Imager, J. Clim., 10, 1086–1098, 1997. Young, K C.: A Numerical Simulation of Wintertime, Orographic Precipitation: Part I. Description of Model Microphysics and Numerical Techniques, J. Atmos. Sci., 31, 1735–1748, 1974.