ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-5985-2012 Aerosol indirect effects from shipping emissions: sensitivity studies with the global aerosol-climate model ECHAM-HAM Peters K. 1 2 5 Stier P. 3 Quaas J. 4 Graßl H. 1 Max Planck Institute for Meteorology, Hamburg, Germany International Max Planck Research School on Earth System Modelling, Hamburg, Germany Department of Physics, University of Oxford, UK Institute for Meteorology, University of Leipzig, Leipzig, Germany now at: Monash University, School of Mathematical Sciences, Clayton, VIC 3800, Australia 13 07 2012 12 13 5985 6007 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/12/5985/2012/acp-12-5985-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/5985/2012/acp-12-5985-2012.pdf

In this study, we employ the global aerosol-climate model ECHAM-HAM to globally assess aerosol indirect effects (AIEs) resulting from shipping emissions of aerosols and aerosol precursor gases. We implement shipping emissions of sulphur dioxide (SO<sub>2</sub>), black carbon (BC) and particulate organic matter (POM) for the year 2000 into the model and quantify the model's sensitivity towards uncertainties associated with the emission parameterisation as well as with the shipping emissions themselves. Sensitivity experiments are designed to investigate (i) the uncertainty in the size distribution of emitted particles, (ii) the uncertainty associated with the total amount of emissions, and (iii) the impact of reducing carbonaceous emissions from ships. <br><br> We use the results from one sensitivity experiment for a detailed discussion of shipping-induced changes in the global aerosol system as well as the resulting impact on cloud properties. From all sensitivity experiments, we find AIEs from shipping emissions to range from −0.32 ± 0.01 W m<sup>−2</sup> to −0.07 ± 0.01 W m<sup>−2</sup> (global mean value and inter-annual variability as a standard deviation). The magnitude of the AIEs depends much more on the assumed emission size distribution and subsequent aerosol microphysical interactions than on the magnitude of the emissions themselves. It is important to note that although the strongest estimate of AIEs from shipping emissions in this study is relatively large, still much larger estimates have been reported in the literature before on the basis of modelling studies. We find that omitting just carbonaceous particle emissions from ships favours new particle formation in the boundary layer. These newly formed particles contribute just about as much to the CCN budget as the carbonaceous particles would, leaving the globally averaged AIEs nearly unaltered compared to a simulation including carbonaceous particle emissions from ships.

 References Abdul-Razzak, H. and Ghan, S.: A parameterization of aerosol activation 2. Multiple aerosol types, J. Geophys. Res., 105, 6837–6844, http://dx.doi.org/10.1029/1999JD901161doi:10.1029/1999JD901161, 2000. Agrawal, H., Malloy, Q., Welch, W., Wayne~Miller, J., and Cocker~III, D.: In-use gaseous and particulate matter emissions from a modern ocean going container vessel, Atmos. Environ., 42, 5504–5510, http://dx.doi.org/10.1016/j.atmosenv.2008.02.053doi:10.1016/j.atmosenv.2008.02.053, 2008. Agrawal, H., Welch, W., Henningsen, S., Miller, J., and Cocker~III, D.: Emissions from main propulsion engine on container ship at sea, J. Geophys. Res, 115, D23205, http://dx.doi.org/10.1029/2009JD013346doi:10.1029/2009JD013346, 2010. Albrecht, B A.: Aerosols, Cloud Microphysics, and Fractional Cloudiness, Science, 245, 1227–1230, 1989. Ångström, A.: Atmospheric turbidity, global illumination and planetary albedo of the earth, Tellus, 14, 435–450, 1962. Balkanski, Y., Myhre, G., Gauss, M., Rädel, G., Highwood, E. J., and Shine, K. P.: Direct radiative effect of aerosols emitted by transport: from road, shipping and aviation, Atmos. Chem. Phys., 10, 4477–4489, http://dx.doi.org/10.5194/acp-10-4477-2010doi:10.5194/acp-10-4477-2010, 2010. Behrens, H L.: Present Traffic and Emissions from Maritime Shipping, in: Deliverable D1.1.2.2 of the EU-IP QUANTIFY (confidential), Det Norske Veritas, http://www.pa.op.dlr.de/quantify/, 2006. Bond, T.: Can warming particles enter global climate discussions?, Environ. Res. Lett., 2, 045030, http://dx.doi.org/10.1088/1748-9326/2/4/045030doi:10.1088/1748-9326/2/4/045030, 2007. Bond, T., Streets, D., Yarber, K., Nelson, S., Woo, J., and Klimont, Z.: A technology-based global inventory of black and organic carbon emissions from combustion, J. Geophys. Res, 109, D14203, http://dx.doi.org/10.1029/2003JD003697doi:10.1029/2003JD003697, 2004. Borken-Kleefeld, J., Berntsen, T., and Fuglestvedt, J.: Specific climate impact of passenger and freight transport, Environ. Sci. Technol., 44, 5700–5706, http://dx.doi.org/10.1021/es9039693doi:10.1021/es9039693, 2010. Buhaug, Ø., Corbett, J., Endresen, Ø., Eyring, V., Faber, J., Hanayama, S., Lee, D., Lee, D., Lindstad, H., Markowska, A., Mjelde, A., Nelissen, D., Nilsen, J., Pålsson, C., Winebrake, J., Wu, W.-Q., and Yoshida, K.: Second IMO GHG study 2009, International Maritime Organization (IMO), London, UK, 24, 2009. Capaldo, K., Corbett, J., Kasibhatla, P., Fischbeck, P., and Pandis, S.: Effects of ship emissions on sulphur cycling and radiative climate forcing over the ocean, Nature, 400, 743–746, 1999. Christensen, M. and Stephens, G.: Microphysical and macrophysical responses of marine stratocumulus polluted by underlying ships: Evidence of cloud deepening, J. Geophys. Res.-Atmos., 116, D03201, http://dx.doi.org/10.1029/2010JD014638doi:10.1029/2010JD014638, 2011. Corbett, J. and Koehler, H.: Updated emissions from ocean shipping, J. Geophys. Res, 108, 4650–4664, 2003. Corbett, J. and Koehler, H.: Considering alternative input parameters in an activity-based ship fuel consumption and emissions model: Reply to comment by Øyvind Endresen et al. on Updated emissions from ocean shipping, J. Geophys. Res., 109, D23303, http://dx.doi.org/10.1029/2004JD005030doi:10.1029/2004JD005030, 2004. Corbett, J., Fischbeck, P., and Pandis, S.: Global nitrogen and sulfur inventories for oceangoing ships, J. Geophys. Res, 104, 3457–3470, http://dx.doi.org/10.1029/1998JD100040doi:10.1029/1998JD100040, 1999. Dalsøren, S. B., Eide, M. S., Endresen, Ø., Mjelde, A., Gravir, G., and Isaksen, I. S. A.: Update on emissions and environmental impacts from the international fleet of ships: the contribution from major ship types and ports, Atmos. Chem. Phys., 9, 2171–2194, http://dx.doi.org/10.5194/acp-9-2171-2009doi:10.5194/acp-9-2171-2009, 2009. Dentener, F., Kinne, S., Bond, T., Boucher, O., Cofala, J., Generoso, S., Ginoux, P., Gong, S., Hoelzemann, J. J., Ito, A., Marelli, L., Penner, J. E., Putaud, J.-P., Textor, C., Schulz, M., van der Werf, G. R., and Wilson, J.: Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data-sets for AeroCom, Atmos. Chem. Phys., 6, 4321–4344, http://dx.doi.org/10.5194/acp-6-4321-2006doi:10.5194/acp-6-4321-2006, 2006. Devasthale, A., Krüger, O., and Grassl, H.: Change in Cloud-Top Temperatures Over Europe, IEEE Geosci. Remote S., 2, 333–336, http://dx.doi.org/10.1109/LGRS.2005.851736doi:10.1109/LGRS.2005.851736, 2005. Devasthale, A., Krüger, O., and Grassl, H.: Impact of ship emissions on cloud properties over coastal areas, Geophys. Res. Lett., 33, L02811, http://dx.doi.org/10.1029/2005GL024470doi:10.1029/2005GL024470, 2006. Endresen, Ø., Sørgård, E., Sundet, J., Dalsøren, S., Isaksen, I., Berglen, T., and Gravir, G.: Emission from international sea transportation and environmental impact, J. Geophys. Res., 108, 4560, http://dx.doi.org/10.1029/2002JD002898doi:10.1029/2002JD002898, 2003. Endresen, Ø., Sørgård, E., Bakke, J., and Isaksen, I.: Substantiation of a lower estimate for the bunker inventory: Comment on Updated emissions from ocean shipping by James J. Corbett and Horst W. Koehler, J. Geophys. Res., 109, D23302, http://dx.doi.org/10.1029/2004JD004853doi:10.1029/2004JD004853, 2004. Eyring, V., Köhler, H., Lauer, A., and Lemper, B.: Emissions from international shipping: 2. Impact of future technologies on scenarios until 2050, J. Geophys. Res., 110, D17306, http://dx.doi.org/10.1029/2004JD005620doi:10.1029/2004JD005620, 2005a. Eyring, V., Köhler, H., Van~Aardenne, J., and Lauer, A.: Emissions from international shipping: 1. The last 50 years, J. Geophys. Res., 110, D17305, http://dx.doi.org/10.1029/2004JD005619doi:10.1029/2004JD005619, 2005b. Eyring, V., Isaksen, I. S A., Berntsen, T., Collins, W J., Corbett, J J., Endresen, O., Grainger, R G., Moldanova, J., Schlager, H., and Stevenson, D S.: Transport impacts on atmosphere and climate: Shipping, Atmos. Environ., 44, 4735–4771, http://dx.doi.org/10.1016/j.atmosenv.2009.04.059doi:10.1016/j.atmosenv.2009.04.059, 2010. Feichter, J., Kjellström, E., Rodhe, H., Dentener, F., Lelieveldi, J., and Roelofs, G.: Simulation of the tropospheric sulfur cycle in a global climate model, Atmos. Environ., 30, 1693–1707, 1996. Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D W., Haywood, J., Lean, J., Lowe, D C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M., and Van~Dorland, R.: Changes in Atmospheric Constituents and in Radiative Forcing, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K B., Tignor, M., and Miller, H L., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2007. Franke, K., Eyring, V., Sander, R., Hendricks, J., Lauer, A., and Sausen, R.: Toward effective emissions of ships in global models, Meteorol. Z., 17, 117–129, http://dx.doi.org/10.1127/0941-2948/2008/0277doi:10.1127/0941-2948/2008/0277, 2008. Fuglestvedt, J., Berntsen, T., Eyring, V., Isaksen, I., Lee, D S., and Sausen, R.: Shipping Emissions: From Cooling to Warming of Climate – and Reducing Impacts on Health, Environ. Sci. Technol., 43, 9057–9062, http://dx.doi.org/10.1021/es901944rdoi:10.1021/es901944r, 2009. Gehlot, S. and Quaas, J.: Convection-climate feedbacks in the ECHAM5 general circulation model: Evaluation of cirrus cloud life cycles with ISCCP satellite data from a Lagrangian trajectory perspective, J. Climate, http://dx.doi.org/10.1175/JCLI-D-11-00345.1doi:10.1175/JCLI-D-11-00345.1, in press, 2012. 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, 27509–27524, 2001. Horowitz, L., Walters, S., Mauzerall, D., Emmons, L., Rasch, P., Granier, C., Tie, X., Lamarque, J., Schultz, M., Tyndall, G., Orlando, J., and Brasseur, G.: A global simulation of tropospheric ozone and related tracers: Description and evaluation of MOZART, version 2, J. Geophys. Res, 108, 4784, http://dx.doi.org/10.1029/2002JD002853doi:10.1029/2002JD002853, 2003. Huszar, P., Cariolle, D., Paoli, R., Halenka, T., Belda, M., Schlager, H., Miksovsky, J., and Pisoft, P.: Modeling the regional impact of ship emissions on NO<sub>x</sub> and ozone levels over the Eastern Atlantic and Western Europe using ship plume parameterization, Atmos. Chem. Phys., 10, 6645–6660, http://dx.doi.org/10.5194/acp-10-6645-2010doi:10.5194/acp-10-6645-2010, 2010. IMO: Regulations for the prevention of air pollution from ships and NO$_\textx$ technical code, ANNEX IV of MARPOL 73/78, Tech. rep., London, 1998. Kazil, J. and Lovejoy, E. R.: A semi-analytical method for calculating rates of new sulfate aerosol formation from the gas phase, Atmos. Chem. Phys., 7, 3447–3459, http://dx.doi.org/10.5194/acp-7-3447-2007doi:10.5194/acp-7-3447-2007, 2007. Kazil, J., Stier, P., Zhang, K., Quaas, J., Kinne, S., O'Donnell, D., Rast, S., Esch, M., Ferrachat, S., Lohmann, U., and Feichter, J.: Aerosol nucleation and its role for clouds and Earth's radiative forcing in the aerosol-climate model ECHAM5-HAM, Atmos. Chem. Phys., 10, 10733–10752, http://dx.doi.org/10.5194/acp-10-10733-2010doi:10.5194/acp-10-10733-2010, 2010. Kettle, A. and Andreae, M.: Flux of dimethylsulfide from the oceans- A comparison of updated data sets and flux models, J. Geophys. Res., 105, 793–808, 2000. 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. Kinne, S., Schulz, M., Textor, C., Guibert, S., Balkanski, Y., Bauer, S. E., Berntsen, T., Berglen, T. F., Boucher, O., Chin, M., Collins, W., Dentener, F., Diehl, T., Easter, R., Feichter, J., Fillmore, D., Ghan, S., Ginoux, P., Gong, S., Grini, A., Hendricks, J., Herzog, M., Horowitz, L., Isaksen, I., Iversen, T., Kirkevåg, A., Kloster, S., Koch, D., Kristjansson, J. E., Krol, M., Lauer, A., Lamarque, J. F., Lesins, G., Liu, X., Lohmann, U., Montanaro, V., Myhre, G., Penner, J., Pitari, G., Reddy, S., Seland, O., Stier, P., Takemura, T., and Tie, X.: An AeroCom initial assessment – optical properties in aerosol component modules of global models, Atmos. Chem. Phys., 6, 1815–1834, http://dx.doi.org/10.5194/acp-6-1815-2006doi:10.5194/acp-6-1815-2006, 2006. Kireeva, E., Popovicheva, O., Persiantseva, N., Timofeyev, M., and Shonija, N.: Fractionation analysis of transport engine-generated soot particles with respect to hygroscopicity, J. Atmos. Chem., 64, 129–147, http://dx.doi.org/10.1007/s10874-010-9173-ydoi:10.1007/s10874-010-9173-y, 2010. Koch, D. and Del Genio, A. D.: Black carbon semi-direct effects on cloud cover: review and synthesis, Atmos. Chem. Phys., 10, 7685–7696, http://dx.doi.org/10.5194/acp-10-7685-2010doi:10.5194/acp-10-7685-2010, 2010. Koren, I., Kaufman, Y., Rosenfeld, D., Remer, L., and Rudich, Y.: Aerosol invigoration and restructuring of Atlantic convective clouds, Geophys. Res. Lett., 32, L14828, http://dx.doi.org/10.1029/2005GL023187doi:10.1029/2005GL023187, 2005. Kulmala, M., Lehtinen, K. E. J., and Laaksonen, A.: Cluster activation theory as an explanation of the linear dependence between formation rate of 3 nm particles and sulphuric acid concentration, Atmos. Chem. Phys., 6, 787–793, http://dx.doi.org/10.5194/acp-6-787-2006doi:10.5194/acp-6-787-2006, 2006. Kyoto Protocol: Kyoto Protocol to the United Nations Framework Convention on Climate Change, United Nations Publications: Geneva, Switzerland, 1997. Lack, D. A. and Corbett, J. J.: Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing, Atmos. Chem. Phys., 12, 3985–4000, http://dx.doi.org/10.5194/acp-12-3985-2012doi:10.5194/acp-12-3985-2012, 2012. Lack, D A., Corbett, J J., Onasch, T., Lerner, B., Massoli, P., Quinn, P K., Bates, T S., Covert, D S., Coffman, D., Sierau, B., Herndon, S., Allan, J., Baynard, T., Lovejoy, E., Ravishankara, A R., and Williams, E.: Particulate emissions from commercial shipping: Chemical, physical, and optical properties, J. Geophys. Res.-Atmos., 114, D00F04, http://dx.doi.org/10.1029/2008JD011300doi:10.1029/2008JD011300, 2009. Lamarque, J.-F., Bond, T. C., Eyring, V., Granier, C., Heil, A., Klimont, Z., Lee, D., Liousse, C., Mieville, A., Owen, B., Schultz, M. G., Shindell, D., Smith, S. J., Stehfest, E., Van Aardenne, J., Cooper, O. R., Kainuma, M., Mahowald, N., McConnell, J. R., Naik, V., Riahi, K., and van Vuuren, D. P.: Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application, Atmos. Chem. Phys., 10, 7017–7039, http://dx.doi.org/10.5194/acp-10-7017-2010doi:10.5194/acp-10-7017-2010, 2010. Lauer, A., Eyring, V., Hendricks, J., Jöckel, P., and Lohmann, U.: Global model simulations of the impact of ocean-going ships on aerosols, clouds, and the radiation budget, Atmos. Chem. Phys., 7, 5061–5079, http://dx.doi.org/10.5194/acp-7-5061-2007doi:10.5194/acp-7-5061-2007, 2007. Lauer, A., Eyring, V., Corbett, J., Wang, C., and Winebrake, J.: Assessment of Near-Future Policy Instruments for Oceangoing Shipping: Impact on Atmospheric Aerosol Burdens and the Earth's Radiation Budget, Environ. Sci. Technol., 43, 5592–5598, http://dx.doi.org/10.1021/es900922hdoi:10.1021/es900922h, 2009. Lin, H. and Leaitch, W.: Development of an in-cloud aerosol activation parameterization for climate modelling, in: Proceedings of the WMO Workshop on Measurement of Cloud Properties for Forecasts of Weather, Air Quality and Climate, Mexico City, 328–335, 1997. Lin, S. and Rood, R.: Multidimensional flux-form semi-Lagrangian transport schemes, Mon. Weather Rev., 124, 2046–2070, 1996. 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, http://dx.doi.org/10.5194/acp-7-3425-2007doi:10.5194/acp-7-3425-2007, 2007. Lohmann, U., Rotstayn, L., Storelvmo, T., Jones, A., Menon, S., Quaas, J., Ekman, A. M. L., Koch, D., and Ruedy, R.: Total aerosol effect: radiative forcing or radiative flux perturbation?, Atmos. Chem. Phys., 10, 3235–3246, http://dx.doi.org/10.5194/acp-10-3235-2010doi:10.5194/acp-10-3235-2010, 2010. Myhre, G.: Consistency between satellite-derived and modeled estimates of the direct aerosol effect, Science, 325, 187, http://dx.doi.org/10.1126/science.1174461doi:10.1126/science.1174461, 2009. Nam, C. C.-W.: Using CALIPSO and CloudSat satellite retrievals to evaluate low-level cloud parameterizations in ECHAM5 for cloud-climate feedbacks implications, in: Berichte zur Erdsystemforschung, 88, 132 pp., ISSN: 1614-1199, Max-Planck-Institut für Meteorologie, 2011. Nam, C. C W. and Quaas, J.: Evaluation of clouds and precipitation in the ECHAM5 general circulation model using CALIPSO and CloudSat satellite data, J. Climate, http://dx.doi.org/10.1175/JCLI-D-11-00347.1doi:10.1175/JCLI-D-11-00347.1, in press, 2012. Nordeng, T.: Extended versions of the convective parametrization scheme at ECMWF and their impact on the mean and transient activity of the model in the tropics, in: Tech. Memo., 206, European Centre for Medium-Range Weather Forecasts, Reading, UK, 1994. Olivier, J. G J., Van Aardenne, J A., Dentener, F J., Pagliari, V., Ganzeveld, L N., and Peters, J. A. H W.: Recent trends in global greenhouse gas emissions:regional trends 1970–2000 and spatial distributionof key sources in 2000, Environ. Sci., 2, 81–99, http://dx.doi.org/10.1080/15693430500400345doi:10.1080/15693430500400345, 2005. Paoli, R., Cariolle, D., and Sausen, R.: Review of effective emissions modeling and computation, Geosci. Model Dev., 4, 643–667, http://dx.doi.org/10.5194/gmd-4-643-2011doi:10.5194/gmd-4-643-2011, 2011. Penner, J. E., Quaas, J., Storelvmo, T., Takemura, T., Boucher, O., Guo, H., Kirkevåg, A., Kristjánsson, J. E., and Seland, Ø.: Model intercomparison of indirect aerosol effects, Atmos. Chem. Phys., 6, 3391–3405, http://dx.doi.org/10.5194/acp-6-3391-2006doi:10.5194/acp-6-3391-2006, 2006. Peters, K., Quaas, J., and Bellouin, N.: Effects of absorbing aerosols in cloudy skies: a satellite study over the Atlantic Ocean, Atmos. Chem. Phys., 11, 1393–1404, http://dx.doi.org/10.5194/acp-11-1393-2011doi:10.5194/acp-11-1393-2011, 2011a. Peters, K., Quaas, J., and Graßl, H.: A search for large-scale effects of ship emissions on clouds and radiation in satellite data, J. Geophys. Res.-Atmos., 116, D24205, http://dx.doi.org/10.1029/2011JD016531doi:10.1029/2011JD016531, 2011b. Petzold, A., Hasselbach, J., Lauer, P., Baumann, R., Franke, K., Gurk, C., Schlager, H., and Weingartner, E.: Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer, Atmos. Chem. Phys., 8, 2387–2403, http://dx.doi.org/10.5194/acp-8-2387-2008doi:10.5194/acp-8-2387-2008, 2008. Pierce, J. R. and Adams, P. J.: Uncertainty in global CCN concentrations from uncertain aerosol nucleation and primary emission rates, Atmos. Chem. Phys., 9, 1339–1356, http://dx.doi.org/10.5194/acp-9-1339-2009doi:10.5194/acp-9-1339-2009, 2009. Pierce, J. R., Chen, K., and Adams, P. J.: Contribution of primary carbonaceous aerosol to cloud condensation nuclei: processes and uncertainties evaluated with a global aerosol microphysics model, Atmos. Chem. Phys., 7, 5447–5466, http://dx.doi.org/10.5194/acp-7-5447-2007doi:10.5194/acp-7-5447-2007, 2007. Quaas, J.: Evaluating the "critical relative humidity" as a measure of subgrid-scale variability of humidity in general circulation model cloud cover parameterizations using satellite data, J. Gephys. Res., 117, D09208, http://dx.doi.org/10.1029/2012JD017495doi:10.1029/2012JD017495, 2012. Quaas, J., Ming, Y., Menon, S., Takemura, T., Wang, M., Penner, J. E., Gettelman, A., Lohmann, U., Bellouin, N., Boucher, O., Sayer, A. M., Thomas, G. E., McComiskey, A., Feingold, G., Hoose, C., Kristjánsson, J. E., Liu, X., Balkanski, Y., Donner, L. J., Ginoux, P. A., Stier, P., Grandey, B., Feichter, J., Sednev, I., Bauer, S. E., Koch, D., Grainger, R. G., Kirkevåg, A., Iversen, T., Seland, Ø., Easter, R., Ghan, S. J., Rasch, P. J., Morrison, H., Lamarque, J.-F., Iacono, M. J., Kinne, S., and Schulz, M.: Aerosol indirect effects – general circulation model intercomparison and evaluation with satellite data, Atmos. Chem. Phys., 9, 8697–8717, http://dx.doi.org/10.5194/acp-9-8697-2009doi:10.5194/acp-9-8697-2009, 2009. Righi, M., Klinger, C., Eyring, V., Hendricks, J., Lauer, A., and Petzold, A.: Climate Impact of Biofuels in Shipping: Global Model Studies of the Aerosol Indirect Effect, Environ. Sci. Technol., 45, 3519–3525, http://dx.doi.org/10.1021/es1036157doi:10.1021/es1036157, 2011. Sandu, I., Stevens, B., and Pincus, R.: On the transitions in marine boundary layer cloudiness, Atmos. Chem. Phys., 10, 2377–2391, http://dx.doi.org/10.5194/acp-10-2377-2010doi:10.5194/acp-10-2377-2010, 2010. Schreier, M., Mannstein, H., Eyring, V., and Bovensmann, H.: Global ship track distribution and radiative forcing from 1 year of AATSR data, Geophys. Res. Lett., 34, L17814, http://dx.doi.org/10.1029/2007GL030664doi:10.1029/2007GL030664, 2007. Simmons, A., Uppala, S., Dee, D., and Kobayashi, S.: ERA-Interim: New ECMWF reanalysis products from 1989 onwards, ECMWF Newsletter, 110, 25–35, 2007. Small, J., Chuang, P., Feingold, G., and Jiang, H.: Can aerosol decrease cloud lifetime?, Geophys. Res. Lett., 36, L16806, http://dx.doi.org/10.1029/2009GL038888doi:10.1029/2009GL038888, 2009. Spracklen, D. V., Carslaw, K. S., Pöschl, U., Rap, A., and Forster, P. M.: Global cloud condensation nuclei influenced by carbonaceous combustion aerosol, Atmos. Chem. Phys., 11, 9067–9087, http://dx.doi.org/10.5194/acp-11-9067-2011doi:10.5194/acp-11-9067-2011, 2011. Stevens, B. and Feingold, G.: Untangling aerosol effects on clouds and precipitation in a buffered system, Nature, 461, 607–613, http://dx.doi.org/10.1038/nature08281doi:10.1038/nature08281, 2009. Stevens, R. G., Pierce, J. R., Brock, C. A., Reed, M. K., Crawford, J. H., Holloway, J. S., Ryerson, T. B., Huey, L. G., and Nowak, J. B.: Nucleation and growth of sulfate aerosol in coal-fired power plant plumes: sensitivity to background aerosol and meteorology, Atmos. Chem. Phys., 12, 189–206, http://dx.doi.org/10.5194/acp-12-189-2012doi:10.5194/acp-12-189-2012, 2012. 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, http://dx.doi.org/10.5194/acp-5-1125-2005doi:10.5194/acp-5-1125-2005, 2005. Stier, P., Feichter, J., Kloster, S., Vignati, E., and Wilson, J.: Emission-induced nonlinearities in the global aerosol system: Results from the ECHAM5-HAM aerosol-climate model, J. Climate, 19, 3845–3862, 2006a. Stier, P., Seinfeld, J H., Kinne, S., Feichter, J., and Boucher, O.: Impact of nonabsorbing anthropogenic aerosols on clear-sky atmospheric absorption, J. Geophys. Res., 111, D18201, http://dx.doi.org/10.1029/2006JD007147doi:10.1029/2006JD007147, 2006b. Sundqvist, H., Berge, E., and Kristjansson, J.: Condensation and cloud parameterization studies with a mesoscale numerical weather prediction model, Mon. Weather Rev., 117, 1641–1657, 1989. Taylor, K., Williamson, D., and Zwiers, F.: The sea surface temperature and sea-ice concentration boundary conditions for AMIP II simulations, PCMDI Rep, 60, 28, 2000. Tegen, I., Harrison, S., Kohfeld, K., Prentice, I., Coe, M., and Heimann, M.: Impact of vegetation and preferential source areas on global dust aerosol: Results from a model study, J. Geophys. Res, 107, 4576, http://dx.doi.org/10.1029/2001JD000963doi:10.1029/2001JD000963, 2002. 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, http://dx.doi.org/10.5194/acp-6-1777-2006doi:10.5194/acp-6-1777-2006, 2006. Tiedtke, M.: A comprehensive mass flux scheme for cumulus parameterization in large- scale models, Mon. Weather Rev., 117, 1779–1800, 1989. Tompkins, A.: 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. Twomey, S.: Pollution and the planetary albedo, Atmos. Environ., 8, 1251–1256, 1974. Vignati, E., Wilson, J., and Stier, P.: M7: An efficient size-resolved aerosol microphysics module for large-scale aerosol transport models, J. Geophys. Res, 109, D22202, http://dx.doi.org/10.1029/2003JD004485doi:10.1029/2003JD004485, 2004. Wang, C., Corbett, J., and Firestone, J.: Improving spatial representation of global ship emissions inventories, Environ. Sci. Technol, 42, 193–199, http://dx.doi.org/10.1021/es0700799doi:10.1021/es0700799, 2007. Wang, H. and Feingold, G.: Modeling Mesoscale Cellular Structures and Drizzle in Marine Stratocumulus. Part II: The Microphysics and Dynamics of the Boundary Region between Open and Closed Cells, J. Atmos. Sci., 66, 3257–3275, http://dx.doi.org/10.1175/2009JAS3120.1doi:10.1175/2009JAS3120.1, 2009. Wilcox, E. M.: Stratocumulus cloud thickening beneath layers of absorbing smoke aerosol, Atmos. Chem. Phys., 10, 11769–11777, http://dx.doi.org/10.5194/acp-10-11769-2010doi:10.5194/acp-10-11769-2010, 2010. Zhang, K., O'Donnell, D., Kazil, J., Stier, P., Kinne, S., Lohmann, U., Ferrachat, S., Croft, B., Quaas, J., Wan, H., Rast, S., and Feichter, J.: The global aerosol-climate model ECHAM-HAM, version 2: sensitivity to improvements in process representations, Atmos. Chem. Phys. Discuss., 12, 7545–7615, http://dx.doi.org/10.5194/acpd-12-7545-2012doi:10.5194/acpd-12-7545-2012, 2012.