ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-6819-2010 Thunderstorm and stratocumulus: how does their contrasting morphology affect their interactions with aerosols? Lee S. S. 1 Donner L. J. 2 3 Penner J. E. 1 3 Department of Atmospheric, Oceanic, and Space Science, University of Michigan, Ann Arbor, MI, USA Geophysical Fluid Dynamics Laboratory, Princeton University, Princeton, NJ, USA These authors contributed equally to this work. 23 07 2010 10 14 6819 6837 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/10/6819/2010/acp-10-6819-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/6819/2010/acp-10-6819-2010.pdf

It is well-known that aerosols affect clouds and that the effect of aerosols on clouds is critical for understanding human-induced climate change. Most climate model studies have focused on the effect of aerosols on warm stratiform clouds (e.g., stratocumulus clouds) for the prediction of climate change. However, systems like the Asian and Indian Monsoon, storm tracks, and the intertropical convergence zone, play important roles in the global hydrological cycle and in the circulation of energy and are driven by thunderstorm-type convective clouds. Here, we show that the different morphologies of these two cloud types lead to different aerosol-cloud interactions. Increasing aerosols are known to suppress the conversion of droplets to rain (i.e., so-called autoconversion). This increases droplets as a source of evaporative cooling, leading to an increased intensity of downdrafts. The acceleration of the intensity of downdrafts is larger in convective clouds due to their larger cloud depths (providing longer paths for downdrafts to follow to the surface) than in stratiform clouds. More accelerated downdrafts intensify the gust front, leading to significantly increased updrafts, condensation and thus the collection of cloud liquid by precipitation, which offsets the suppressed autoconversion. This leads to an enhancement of precipitation with increased aerosols in convective clouds. However, the downdrafts are less accelerated in stratiform clouds due to their smaller cloud depths, and they are not able to induce changes in updrafts as large as those in convective clouds. Thus, the offset is not as effective, and this allows the suppression of precipitation with increased aerosols. Thus aerosols affect these cloud systems differently. The dependence of the effect of aerosols on clouds on the morphology of clouds should be taken into account for a more complete assessment of climate change.

 References % vor jede Referenz Abdul-Razzak, H. and Ghan, S. J.: A parameterization of aerosol activation 2. Multiple aerosol types, J. Geophys. Res., 105, 6837–6844, 2000. Abdul-Razzak, H. and Ghan, S. J.: A parameterization of aerosol activation - 3. Sectional representation, J. Geophys. Res., 107, 4026, doi:10.1029/2001JD000483, 2002. Albrecht, B. A.: Aerosols, cloud microphysics, and fractional cloudiness, Science, 245, 1227–1230, 1989. Bell, T. L., Rosenfeld, D., Kim, K.-M., Yoo, J.-M., Lee, M.-I., and Hahnenberger, M.: Midweek increase in U.S. summer rain and storm heights suggests air pollution invigorates rainstorms, J. Geophys. Res., 113, D02209, doi:10.1029/2007JD008623, 2008. Bluestein, H. B.: Synoptic-Dynamic Meteorology in Midlatitudes: Volume II: Observations and Theory of Weather Systems (Synoptic-Dynamic Meteorology in Midlatitudes), Oxford University Press, 594~pp., 1993. Chin, M., Ginoux, P., Kinne, S., et al.: Tropospheric Aerosol Optical Thickness from the GOCART Model and Comparisons with Satellite and Sun Photometer Measurements, J. Atmos. Sci., 59, 441–460, 2002. Chou, M.-D. and Suarez, M. J.: A shortwave radiation parameterization for atmospheric studies. 15, NASA/TM-104606, 40~pp, 1999. Chou, M.-D., Ridgway, W., and Yan, M.-H: Parameterizations for water vapor IR radiative transfer in both the middle and lower atmospheres, J. Atmos. Sci., 52, 1159–1167, 1999. DeMott, P. J., Cziczo, D. J., Prenni, A. J., Murphy, D. M., Kreidenweis, S. M., Thomson, D. S., Borys, R., and Rogers, D. C.: Measurements of the concentration and composition of nuclei for cirrus formation, P. Natl. Acad. Sci. USA, 100(25), 14655–14660, 2003. Fan, J., Yuan, T., Comstock, J. M., et al.: Dominant role by vertical wind shear in regulating aerosol effects on deep convective clouds, J. Geophys. Res., 114, D22206, doi:10.1029/20009JD012352, 2009. Feingold, G., Tzivion, S., and Levin, Z.: Evolution of raindrop spectra. Part I: Solution to the stochastic collection/breakup equation using the method of moments, J. Atmos. Sci., 45, 3387–3399, 1988. Feingold, G., Cotton, W., Kreidenweis, S., and Davis, J.: The impact of giant cloud condensation nuclei on drizzle formation in stratocumulus: Implications for cloud radiative properties. J. Atmos. Sci., 56, 4100–4117, 1999. Field, P. R., Möhler, O., Connolly, P., Krämer, M., Cotton, R., Heymsfield, A. J., Saathoff, H., and Schnaiter, M.: Some ice nucleation characteristics of Asian and Saharan desert dust, Atmos. Chem. Phys., 6, 2991–3006, doi:10.5194/acp-6-2991-2006, 2006. Forster, P., Ramaswamy, V., Artaxo, P., et al.: 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., et al., Cambridge Univ. Press, New York, 2007. Houze, R. A.: Cloud dynamics, Academic Press, 573~pp., 1993. Ghan, S., Laulainen, N., Easter, R., Wagener, R., Nemesure, S., Chapman, E., Zhang, Y., and Leung, R.: Evaluation of aerosol direct radiative forcing in mirage, J. Geophys. Res., 106, 5295–5316, 2001 Grabowski, W. W.: Indirect Impact of Atmospheric Aerosols in Idealized Simulations of Convective – Radiative Quasi Equilibrium, J. Climate, 18, 4664–4682, 2006. Hall, W.: A detailed microphysical model within a two-dimensional dynamic framework: Model description and preliminary results, J. Atmos. Sci., 37, 2486–2507, 1980. Hallett, J. and Mossop, S. C.: Production of secondary ice particles during the riming process, Nature, 249, 26–28, 1974. Harrington, J. Y., Michael, P. M., Walko, R. L., and Cotton, R. C.: Parameterization of ice crystal conversion processes due to vapor deposition for mesoscale models using double-moment basis functions. Part I: Basic formulation and parcel model results, J. Atmos. Sci., 52, 4344–4366, 1995. Heymsfield, A. J., Bansemer, A., Field, P. R., Durden, S. L., Stith, J. L., Dye, J. E., Hall, W., and Grainger, C.: Observations and parameterizations of particle size distribution in deep tropical cirrus and stratiform precipitating clouds: results from in situ observations in TRMM field campaigns, J. Atmos. Sci., 59, 3457–3491, 2005. Houze, R. A.: Cloud dynamics, Academic Press, 573~pp., 1993. Khain, A., Leung, L. R., Lynn, B., and Ghan, S.: Effects of aerosols on the dynamics and microphysics of squall lines simulated by spectral bin and bulk parameterization schemes, J. Geophy. Res., 114, D22203, doi:10.1029/2009JD011902, 2009. Khain, A. and Lynn, B.: Simulation of a supercell storm in clean and dirty atmosphere using weather research and forecast model with spectral bin microphysics, J. Geophy. Res., 114, D19209, doi:10.1029/2009JD011827, 2009. Khain, A., BenMoshe, N., and Pokrovsky, A.: Factors determining the impact of aerosols on surface precipitation from clouds: Attempt of classification, J. Atmos. Sci., 65, 1721–1748, 2008. Khain, A. and Pokrovsky, A.: Simulation of Effects of Atmospheric Aerosols on Deep Turbulent Convective Clouds Using a Spectral Microphysics Mixed-Phase Cumulus Cloud Model. Part II: Sensitivity Study, J. Atmos.Sci., 24, 2983–3001, 2004. Khain, A., Rosenfeld, D., and Pokrovsky, A.: Aerosol impact on the dynamics and microphysics of deep convective clouds, Q. J. Roy. Meteor. Soc., 131, 2639–2663, 2005. Khain, A., Rosenfeld, D., and Pokrovsky, A.: Simulatoins of aerosol effects on convective clouds developed under continental and maritime conditions, Geophys. Res. Abstr., 5, 03180, 2003. Klemp, J. B. and Wilhelmson, R.: The simulation of three-dimensional convective storm dynamics, J. Atmos. Sci., 35, 1070–1096, 1978. Koch, D. and Rind, D.: Beryllium 10/beryllium 7 as a tracer of stratospheric transport, J. Geophys. Res., 103, 3907–3918, 1998. Koren, I., Y. J. Kaufman, Y. J., Rosenfeld, D., L. A. Remer, L. A., and Rudich Y.: Aerosol invigoration and restructuring of Atlantic convective clouds, Geophys. Res. Lett., 32, L14828, doi:10.1029/2005GL023187, 2005. Koop, T., Luo, B. P., Tsias, A., and Peter, T.: Water activity as the determinant for homogeneous ice nucleation in aqueous solutions, Nature, 406, 611–614, 2000. Kratz, D. P., Chou, M.-D., Yan, M.-H., and Ho, C.-H.: Minor trace gas radiative forcing calculations using the k-distribution method with one-parameter scaling, J. Geophy. Res., 103, 31647–31656, 1998. Lee, S. S., Donner, L. J., Phillips, V. T. J., and Ming, Y.: Examination of aerosol effects on precipitation in deep convective clouds during the 1997 ARM summer experiment, Q. J. Roy. Meteor. Soc., 134, 1201–1220, 2008a. Lee, S. S., Donner, L. J., Phillips, V. T. J., and Ming, Y.: The dependence of aerosol effects on clouds and precipitation on cloud-system organization, shear and stability, J. Geophys. Res., 113, D16202, doi:10.1029/2007JD009224, 2008b. Lee, S. S., Donner, L. J., and Phillips, V. T. J.: Sensitivity of aerosol and cloud effects on radiation to cloud types: comparison between deep convective clouds and warm stratiform clouds over one-day period, Atmos. Chem. Phys., 9, 2555–2575, doi:10.5194/acp-9-2555-2009, 2009a. Lee, S. S., Penner, J. E., and Wang, M.: Comparison of a global-climate model simulation to a cloud-system resolving model simulation for long-term thin stratocumulus clouds, Atmos. Chem. Phys., 9, 6497–6520, doi:10.5194/acp-9-6497-2009, 2009b. Lee, S. S. and Penner, J. E.: Comparison of a global-climate model to a cloud-system resolving model for the long-term response of thin stratocumulus clouds to preindustrial and present-day aerosol conditions, Atmos. Chem. Phys., 10, 6371–6389, doi:10.5194/acp-10-6371-2010, 2010. Lee, S. S, Penner, J. E., and Saleeby, S. M.: Aerosol effects on liquid-water path of thin stratocumulus clouds, J. Geophys. Res., 114, D07204, doi:10.1029/2008JD010513, 2009c. Li, X., Tao, W.-K., Khain, A. P., Simpson, J., and Johnson, D. E.: Sensitivity of a Cloud-Resolving Model to Bulk and Explicit Bin Microphysical Schemes. Part I: Comparisons, J. Atmos. Sci., 66, 3–21, 2009a. Li, X., Tao, W.-K., Khain, A. P., Simpson, J., and Johnson, D. E.: Sensitivity of a Cloud-Resolving Model to Bulk and Explicit Bin Microphysical Schemes. Part II: Cloud Microphysics and Storm Dynamics Interactions, J. Atmos. Sci., 66, 22–40, 2009b. Lin, J. C., Matsui, T., Pielke Sr., R. A., and Kummerow, C.: Effects of biomass-burning-derived aerosols on precipitation and clouds in the Amazon Basin: a satellite-based empirical study, J. Geophys. Res., 111, D19204, doi:10.1029/2005JD006884, 2006. Liou, K. N.: Cirrus clouds and climate in McGraw-Hill Yearbook of Science and Technology, 432~pp., 2005. Liou, K. N.: Influence of cirrus clouds on weather and climate processes: A global perspective, Mon. Weather Rev., 114, 1167–1199, 1986. Lohmann, U. and Diehl, K.: Sensitivity studies of the importance of dust ice nuclei for the indirect aerosol effect on stratiform mixed-phase clouds, J. Atmos. Sci., 63, 968–982, 2006. Long, A.: Solutions to the droplet collection equation for polynomial kernels, J. Atmos. Sci., 31, 1040–1052, 1974. Lynn, B. H., Khain, A. P., Dudhia, J., Rosenfeld, D., Pokrovsky, A., and Seifert, A.: Spectral (bin) microphysics coupled with a mesoscale model (MM5). Part I: Model description and first results, Mon. Weather Rev., 133, 44–58, 2005. Meyers, M. P., DeMott, P. J., and Cotton, W. R.: New primary ice-nulceation parameterization in an explicit cloud model, J. Appl. Meteor., 45, 3–39, 1997. Meyers, M. P., Walko, R. L., Harrington, J. Y., and Cotton, W. R.: New RAMS cloud microphysics parameterization: Part II. The two-moment scheme, Atmos. Res., 38, 29–62, 1995. Möhler, O., Field, P. R., Connolly, P., Benz, S., Saathoff, H., Schnaiter, M., Wagner, R., Cotton, R., Krämer, M., Mangold, A., and Heymsfield, A. J.: Efficiency of the deposition mode ice nucleation on mineral dust particles, Atmos. Chem. Phys., 6, 3007–3021, doi:10.5194/acp-6-3007-2006, 2006. Morrison, H., Thomson, G., and Tatarskii, V.: Impact of cloud microphysics on the development of trailing stratiform precipitation in a simulated squall line: Comparison of one- and two-moment schemes, Mon. Weather Rev., 137, 991–1007, 2009. Penner, J. E., Andreae, M., Annegarn, et al.: Report to intergovernmental panel on climate change from the scientific assessment working group (WGI), in climate change 2001: The scientific basis, chap. 5, edited by: Houghton, J. T., Ding, Y., Griggs, D. J., et al., Cambridge Univ. Press, New York, 289–348, 2001. Phillips, V. T. J., Sherwood, S. C., Andronache, C., Bansemer, A., Conant, W. C., DeMott, P. J., et al.: Anvil galciation in a deep cumulus updraft over Florida simulated with an explicit microphysics model. I: The impact of various nucleation processes, Q. J. Roy. Meteorol. Soc, 131, 2019–2046, 2005. Phillips, V. T. J., Donner, L. J., and Garner, S.: Nucleation processes in deep convection simulated by a cloud-system-resolving model with double-moment bulk microphysics, J. Atmos. Sci., 64, 738–761, 2007. Phillips, V. T. J. and Donner, L. J.: Cloud microphysics, radiation and vertical velocities in two- and three-dimensional simulations of deep convection, Q. J. Roy. Meteor. Soc., 132, 3011–3033, 2006. Ramanathan, V., Cess, R. D., Harrison, E. F., et al.: Cloud-Radiative Forcing and Climate: Results from the Earth Radiation Budget Experiment, Science, 243, 57–63, 1989. Ramaswamy, V., Boucher, O., Haigh, J., et al.: Radiative forcing of climate change, in Climate Change 2001: The Scientific Basis, edited by: Houghton, J. T., Ding, Y., Griggs, D. J., et al., Cambridge Univ. Press, New York, 349–416, 2001. Rosenfeld, D., Lohmann, U., Raga, G. B., O'Dowd, C. D., Kulmala, M., Fuzzi, S., Reissell, A., and Andreae, M. O.: Flood or drought: How do aerosols affect precipitation?, Science, 321, 1309–1313, 2008. Saleeby, S. M. and Cotton, W. R.: A large-droplet mode and prognostic number concentration of cloud droplets in the Colorado state university regional atmospheric modeling system (RAMS). Part I: Module description and supercell test simulations, J. Appl. Meteor., 43, 182–195, 2004. Seifert, A., Khain, A., Pokrovsky, A., and Beheng, K. D.: A comparison of spectral and two-moment bulk mixed-phase cloud microphysics, Atmos. Res., 80, 46–66, 2006. Simpson, J. and Tao, W.-K.: The Goddard Cumulus Ensemble model. Part II: Applications for studying cloud precipitating processes and for NASA TRMM, Terr. Atmos. Ocean. Sci., 4, 73–116, 1993. Soong, S.-T. and Ogura, Y.: Response of trade wind cumuli to large-scale processes, J. Atmos. Sci., 37, 2035–2050, 1980. Tao, W.-K., Li, X., Khain, A., Matsui, T., Lang, S., and Simpson, J.: The role of atmospheric aerosol concentration on deep convective precipitation: cloud-resolving model simulations, J. Geophys. Res., 112, D24S18, doi:10.1029/2007JD008728, 2007. Tao, W.-K. and Simpson, J.: The Goddard Cumulus Ensemble model. Part I: Model description, Terr. Atmos. Ocean. Sci., 4, 19–54, 1993. Tao, W.-K., Simpson, J., Baker, D., et al.: Microphysics, radiation and surface processes in the Goddard Cumulus Ensemble (GCE) model, Meteor. and Atmos. Phys., 82, 97–137, 2003. Twomey, S.: The influence of pollution on the shortwave albedo of clouds, J. Atmos. Sci., 34, 1149–1152, 1977. Walko, R. L., Cotton, W. R., Meyers, M. P., and Harrington, J. Y.: New RAMS cloud microphysics parameterization: Part I. The single-moment scheme, Atmos. Res., 38, 29–62, 1995. Weisman, M. L. and Klemp, J. B.: The dependence of Numerically Simulated Convective Storms on Vertical Wind Shear and Buoyancy, Mon. Weather Rev., 110, 504–520, 1982 Wilhelmson, R. B. and Klemp, J. B.: A numerical study of storm splitting that leads to long lived storms, J. Atmos. Sci., 35, 1974–1986, 1978.