ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-4641-2008 Relationship between drizzle rate, liquid water path and droplet concentration at the scale of a stratocumulus cloud system Geoffroy O. 1 Brenguier J.-L. 1 Sandu I. 1 GAME/CNRM (Météo-France, CNRS) 42, av. Gaspard Coriolis, 31057 Toulouse, France 11 08 2008 8 16 4641 4654 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/8/4641/2008/acp-8-4641-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/4641/2008/acp-8-4641-2008.pdf

The recent ACE-2, EPIC and DYCOMS-II field experiments showed that the drizzle precipitation rate of marine stratocumulus scales with the cloud geometrical thickness or liquid water path, and the droplet concentration, when averaged over a domain typical of a GCM grid. This feature is replicated here with large-eddy-simulations using state-of-the-art bulk parameterizations of precipitation formation in stratocumulus clouds. The set of numerical simulations shows scaling relationships similar to the ones derived from the field experiments, especially the one derived from the DYCOMS-II data set. This result suggests that the empirical relationships were not fortuitous and that they reflect the mean effect of cloud physical processes. Such relationships might be more suited to GCM parameterizations of precipitation from shallow clouds than bulk parameterizations of autoconversion, that were initially developed for cloud resolving models.

 References Beheng, K. D.: A parameterization of warm cloud microphysical conversion processes, Atmos. Res. 33, 193–206, 1994. Berry, E. X.: Cloud drop growth by coalescence, J. Atmos. Sci, 24, 688–701, 1967. Berry, E. X. and Reinhardt, R. L.: An analysis of cloud drop growth by collection Part II, Single initial distributions, J. Atmos. Sci, 31, 1825–1831, 1974. Boers, R., Jensen, J. B., and Krummel, P. B.: Microphysical and short-wave radiative structure of stratocumulus over the Southern Ocean: Summer results and seasonal differences, Q. J. Roy. Meteor. Soc., 124, 151–168, 1998. Boucher, O., Treut, H. L., and Baker, M. B.: Precipitation and radiation modeling in a general circulation model: Introduction of cloud microphysical process, J. Geophys. Res, 100D, 16 395–16 414, 1995. Brenguier, J.-L., Baumgardner, D., and Baker, B.: A review and discussion of processing algorithms for FSSP concentration measurements, J. Atmos. Oceanic Technol., 11, 1409–1414, 1994. Brenguier, J.-L., Bourrianne, T., de Araujo Coelho, A., Isbert, R. J., Peytavi, R., Trevarin, D., and Weschler, P.: Improvements of droplet distribution size measurements with the fast-FSSP (forward scattering spectrometer probe), J. Atmos. Oceanic Technol., 15, 1077–1090, 1998. Brenguier, J.-L., Chuang, P. Y., Fouquart, Y., Johnson, D. W., Parol, F., Pawlowska, H., Pelon, J., Schuller, L., Schroder, F., and Snider, J.: An overview of the ACE-2 CLOUDYCOLUMN closure experiment, Tellus B, 52, 815–827, 2000. Brenguier, J.-L., Pawlowska, H., and Schüller, L. J.: Cloud microphysical and radiative properties for parameterization and satellite monitoring of the indirect effect of aerosol on climate, J. Geophys. Res., 108, 8632, 2003. Bretherton, C. S., Uttal, T., Fairall, C. W., Yuter, S., Weller, R., Baumgardner, D., Comstock, K., and Wood, R.: The EPIC 2001 stratocumulus study, Bull. Amer. Meteor. Soc., 85, 967–977, 2004. Charnock, H.: Wind stress over a water surface, Q. J. Roy. Meteor. Soc., 81, 639–640, 1955. Chen, C. and Cotton, W. R.: The physics of the marine stratocumulus mixed layer. J. Atmos. Sci., 44, 2951–2977, 1987. Cohard, J.-M., Pinty, J.-P., and Bedos, C.: Extending Twomey's analytical estimate of nucleated cloud droplet concentrations from CCN spectra, J. Atmos. Sci, 55, 3348–3357, 1998. Cohard J.-M. and Pinty, J.-P.: A comprehensive warm microphysical bulk scheme, part I: Description and selective tests, Q. J. Roy. Meteor. Soc., 126, 1815–1842, 2000. Cohard, J.-M., Pinty, J.-P., and Suhre, K.: On the parameterization of activation spectra from CCN microphycal properties. J. Geophys. Res., 105, 11 753–11 766, 2000. Comstock, K., Wood, R., Yuter, S., and Bretherton, C.: Reflectivity and rain rate in and below drizzling stratocumulus, Q. J. Roy. Meteor. Soc., 130, 2891–2919, 2004. Deardorff, J. W.: Stratocumulus-capped mixed layers derived from a three dimensional model. Boundary-Layer Meteorology, 18, 495–527, 1980. Del Genio, A. D., Yao, M., Kovari, W., and Lo, K. K.: A prognostic cloud water parameterization for climate models, J. Climate, 9, 270–304, 1996. Dong, X. and Mace, G. G.: Arctic stratus cloud properties and radiative forcing derived from ground-based data collected at Barrow, Alaska, J. Climate, 16, 445–460, 2003. Duynkerke, P. G., De Roode, S. R., van Zanten, M. C., Calvo, J., and coauthors: Observations and numerical simulations of the diurnal cycle of the EUROCS stratocumulus case, Q. J. Roy. Meteor. Soc., 130, 3269–3296, 2004. Fairall, C. W., Hare, J. E., and Snider, J. B.: An eight-month sample of marine stratocumulus cloud fraction, albedo, and integrated liquid water, J. Climate, 3, 847–864, 1990. Feingold, G., Stevens, B., Cotton, W. R., and Walko, R. L.: An explicit cloud microphysics/LES model designed to simulate the Twomey effect, Atmos. Res., 33, 207–233, 1994. Feingold, G., Kreidenweis, S. M., Stevens, B., and Cotton, W. R.: Numerical simulation of stratocumulus processing of cloud condensation nuclei through collision-coalescence, J. Geophys. Res., 101, 21 391–21 402, 1996. Feingold, G., Boers, R., Stevens, B., and Cotton, W. R.: A modeling~study of the effect of drizzle on cloud optical depth and~susceptibility, J. Geophys. Res., 102, 13 527–13 534, 1997. Feingold, G. and Kreidenweis, S. M.: Does heterogeneous processing of aerosol increase the number of cloud droplets?, J. Geophys. Res., 105, 24 351–24 361, 2000. Feingold, G. and Kreidenweis, S. M.: Cloud processing of aerosol as modeled by a large eddy simulation with coupled microphysics and aqueous chemistry, J. Geophys. Res., 107, 4687, 2002. Feingold, G. and Chuang, P. Y.: Analysis of the influence of film-forming compounds on droplet growth: Implications for cloud microphysical processes and climate, J. Atmos. Sci., 59, 2006–2018, 2002. Fitzgerald, J. W.: Effect of aerosol composition on cloud droplet size distribution: a numerical study, J. Atmos. Sci., 31, 1358–1367, 1974. Fouquart, Y.: Radiative transfer in climate models, Physically-Based Modeling and Simulation of Climate and Climatic Changes, 223–283, 1987. Fowler, L. D., Randall, D. A., and Rutledge, S. A.: Liquid and ice cloud microphysics in the CSU general circulation model. Part I: Model description and simulated microphysical processes, J. Climate, 9, 489–259, 1996. Gerber, H.: Microphysics of marine stratocumulus clouds with two drizzle modes, J. Atmos. Sci., 53, 1649–1662, 1996. Ghan, S. J. and Easter, R. C.: Computationally efficient approximations to stratiform cloud parameterization, Mon. Wea. Rev., 120, 1572–1582, 1992. Ghan, S. J., Leung, L. R., Easter, R. C., and Razzak, H. A.: Prediction of cloud droplet number in a general circulation model, J. Geophys. Res., 102, 21 777–21 794, 1997. Jiang, H., Feingold, G., and Cotton, W. R.: Simulations of aerosol-cloud-dynamical feedbacks resulting from entrainment of aerosol into the marine boundary layer during the Atlantic Stratocumulus Transition Experiment, J. Geophys. Res., 107, 4813, 2002. Joseph, J. H., Wiscombe, W. J., and Weinman, J. A.: The Delta-Eddington Approximation for Radiative Flux Transfer, J. Atmos. Sci., 33, 2452–2459, 1976. Kessler, E.: On the Distribution and Continuity of Water Substance in Atmospheric Circulations, Meteor. Monogr., 32, Amer. Meteor. Soc., 84 pp., 1969. Khairoutdinov, M. and Kogan, Y.: A new cloud physics parameterization in a large-eddy simulation model of marine stratocumulus, Mon. Wea. Rev., 128, 229–243, 2000. Kogan, Y. L., Lilly, D. K., Kogan, Z. N., and Filyushkin, V. V.: The effect of CNN regeneration on the evolution of stratocumulus cloud layers, Atmos. Res., 33, 137–150, 1994. Kogan, Y. L., Khairoutdinov, M. P., Lilly, D. K., Kogan, Z. N., and Liu, Q.: Modeling of stratocumulus cloud layers in a large eddy simulation model with explicit microphysics, J. Atmos. Sci., 52, 2923–2940, 1995. Lafore, J.-P., Stein, J., Asencio, N., Bougeault, P., Ducrocq, V., Duron, J., Fischer, C., Hereil, P., Mascart, P., Masson, V., Pinty, J.-P., Redelsperger, J.-L., Richard, E., and Vila-Guerau de Arellano, J.: The Méso-NH atmospheric simulation system, Part I: adiabatic formulation and control simulations, Ann. Geophys., 16, 90–109, 1998. Langlois, W. E.: A rapidly convergent procedure for computing large-scale condensation in a dynamical weather model, Tellus, 25, 86–87, 1973. Lipps, F. and Hemler, R. S.: A scale analysis of deep moist convection and some related numerical calculations, J. Atmos. Sci., 39, 2192–2210, 1982. Liu, Q., Kogan, Y. L., Lilly, D. K., Johnson, D. W., Innis, G. E., Durkee, P. A., and Nielsen, K. E.: Modeling of Ship effluent transport and its sensitivity to boundary layer structure, J. Atmos. Sci., 57, 2779–2791, 2000. Liu, Y. and Daum, P. H.: Parameterization of the autoconversion process, Part I: Analytical formulation of the Kessler-type parameterizations, J. Atmos. Sci., 61, 1539–1548, 2004. 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. and Feichter, J.: Impact of sulfate aerosols on albedo and lifetime of clouds: A sensitivity study with the ECHAM4 GCM, J. Geophys. Res., 102D, 13 685–13 700, 1997. Manton, M. J. and Cotton, W. R.: Formulation of approximate equations for modeling moist deep convection on the mesoscale, Atmos. Sci., 266, Dept. of Atmos. Sci., Colorado State University, 1977. Menon, S., Del Genio, A. D., Koch, D., and Tselioudis, G.: GCM simulations of the aerosol indirect effect: Sensitivity to cloud parameterization and aerosol burden, J. Atmos. Sci., 59, 692–713, 2002. Mordy, W. A.: Computations of the growth by condensation of a population of cloud droplets, Tellus, 11, 16–44, 1959. Morcrette, J. J., Smith, L., and Fouquart, Y.: Pressure and temperature dependance of the absorption in longwave radiation parameterizations, Beitr. Phys. Atmosph., 59, 455–469, 1986. Morcrette, J. J.: Radiation and cloud radiative properties in the ECMWF operational weather forecast model, J. Geophys. Res., 96, 9121–9132, 1991. Pawlowska, H. and Brenguier, J.-L.: An observational study of drizzle formation in stratocumulus clouds for general circulation model (GCM) parameterizations, J. Geophys. Res., 108(D15), p. 8630, 2003. Pruppacher, H. R. and Klett, J. D.: Microphysics of Clouds and Precipitation, Kluwer, 954 pp., 1997. Raes, F., Bates, T., McGovern, F., and van Liedekerke, M.: The 2nd Aerosol Characterization Experiment (ACE-2): general overview and main results, Tellus, 52B, 111–125, 2000. Rasch, P. J. and Kristjánsson, J. E.: A comparison of the CCM3 model climate using diagnosed and predicted condensate parameterizations, J. Climate, 11, 1587–1614, 1998. Rotstayn, L. D.: A physically based scheme for the treatment of stratiform clouds and precipitation in large-scale models. I: Description and evaluation of microphysical processes, Q. J. Roy. Meteor. Soc., 123, 1227–1282, 1997. Rotstayn, L. D.: A physically based scheme for the treatment of stratiform clouds and precipitation in large-scale models, II: Comparison of modelled and observed climatological fields, Q. J. Roy. Meteor. Soc., 124, 389–415, 1998. Rotstayn, L. D.: On the "tuning" of the autoconversion parameterizations in climate models, J. Geophys. Res., D105, 15 495–15 507, 2000. Rutledge, S. A. and Hobbs, P. V.: The mesoscale and microscale structure and organizations of clouds and precipitation in midlatitude cyclones Part VIII A model for the seeder feeder process in warm-frontal rainbands, J. Atmos. Sci., 40, 1185–1206, 1983. Savijarvi, H. and Raisanen, P.: Long-wave optical properties of water clouds and rain, Tellus, 50A, 1–11, 1998. Schüller, L., Brenguier J. L., and Pawlowska H.: Retrieval of microphysical, geometrical, and radiative properties of marine stratocumulus from remote sensing, J. Geophys. Res., 108(Db15), p. 8631, 2003. Smith, R. N. B: A scheme for predicting layer clouds and their water content in a general circulation model, Q. J. Roy. Meteor. Soc., 116, 435–460, 1990. Stevens, B., Feingold, G., Cotton, W. R., and Walko, R. L.: Elements of the microphysical structure of numerically simulated stratocumulus, J. Atmos. Sci., 53, 980–1006, 1996. Stevens, B., Cotton, W. R., and Feingold, G.: A critique of one- and two-dimensional models of boundary layer clouds with a binned representations of drop microphysics, Atmos. Res., 47–48 and 529–553, 1998. Stevens, B., Lenschow, D. H., Vali, G., Gerber, H., Bandy, A., Blomquist, B., Brenguier, J.-L., Bretherton, C. S., Burnet, F., Campos, T., Chai, S., Faloona, I., Friesen, D., Haimov, S., Laursen, Lilly, D. K., Loehrer, S., Malinowski, S. P., Morley, B., and Petters, M. D.: Dynamics and chemistry of marine stratocumulus-DYCOMS-II, Bull. Amer. Meteorol. Soc., 84, 579–593, 2003. Stevens, B. and Seifert, A.: Understanding macrophysical outcomes of microphisical choices in simulations of shallow cumulus convection, J. Meteorol. Soc. Jpn., in press, 2008. Sundqvist, H.: A parameterization scheme for non-convective condensation including prediction of cloud water content, Q. J. Roy. Meteor. Soc., 104, 677–690, 1978. Tiedtke, M.: Representation of clouds in large-scale models, Mon. Wea. Rev., 121, 3040–3061, 1993. Tripoli, G. J. and Cotton, W. R.: A numerical investigation of several factors contributing to the observed variable intensity of deep convection over South Florida, J. Atmos. Sci., 19, 1037–1063, 1980. Twomey, S.: The nuclei of natural cloud formation, Part II: The supersaturation in natural clouds and the variation of cloud droplet concentration, Geophys. Pure Appl., 43, 243–249, 1959. van Zanten, M. C., Stevens, B., Vali G., and Lenschow, D. H.: Observations of drizzle in nocturnal marine stratocumulus, J. Atmos. Sci., 62, 88–106, 2005. Wilson, R. D. and Ballard, S. P.: A microphysically based precipitation scheme for the UK Meteorological Office Unified Model, Q. J. Roy. Meteor. Soc., 125, 1607–1636, 1999. Wood, R.: Drizzle in Stratiform Boundary Layer Clouds, Part II: Microphysical Aspects, J. Atmos. Sci., 62, 3034–3050, 2005.