ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-3601-2010 Heterogeneous freezing of droplets with immersed mineral dust particles – measurements and parameterization Niedermeier D. 1 Hartmann S. 1 Shaw R. A. 1 2 Covert D. 3 Mentel T. F. 4 Schneider J. 5 Poulain L. 1 Reitz P. 5 6 Spindler C. 4 Clauss T. 1 Kiselev A. 1 Hallbauer E. 1 Wex H. 1 Mildenberger K. 1 Stratmann F. 1 Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany Department of Physics, Michigan Technological University, Houghton, MI 49931, USA Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, WA 98195, USA ICG-2: Troposphere, Research Center Jülich, 52425 Jülich, Germany Particle Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany Institute for Atmospheric Physics, Johannes Gutenberg University, 55099 Mainz, Germany 19 04 2010 10 8 3601 3614 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/10/3601/2010/acp-10-3601-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/3601/2010/acp-10-3601-2010.pdf

During the measurement campaign FROST (FReezing Of duST), LACIS (Leipzig Aerosol Cloud Interaction Simulator) was used to investigate the immersion freezing behavior of size selected, coated and uncoated Arizona Test Dust (ATD) particles with a mobility diameter of 300 nm. Particles were coated with succinic acid (C<sub>4</sub>H<sub>6</sub>O<sub>4</sub>), sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) and ammonium sulfate ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>). Ice fractions at mixed-phase cloud temperatures ranging from 233.15 K to 239.15 K (&plusmn;0.60 K) were determined for all types of particles. In this temperature range, pure ATD particles and those coated with C<sub>4</sub>H<sub>6</sub>O<sub>4</sub> or small amounts of H<sub>2</sub>SO<sub>4</sub> were found to be the most efficient ice nuclei (IN). ATD particles coated with (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> were the most inefficient IN. Since the supercooled droplets were highly diluted before freezing occurred, a freezing point suppression due to the soluble material on the particles (and therefore in the droplets) cannot explain this observation. Therefore, it is reasonable to assume that the coatings lead to particle surface alterations which cause the differences in the IN abilities. Two different theoretical approaches based on the stochastic and the singular hypotheses were applied to clarify and parameterize the freezing behavior of the particles investigated. Both approaches describe the experimentally determined results, yielding parameters that can subsequently be used to compare our results to those from other studies. However, we cannot clarify at the current state which of the two approaches correctly describes the investigated immersion freezing process. But both approaches confirm the assumption that the coatings lead to particle surface modifications lowering the nucleation efficiency. The stochastic approach interprets the reduction in nucleation rate from coating as primarily due to an increase in the thermodynamic barrier for ice formation (i.e., changes in interfacial free energies). The singular approach interprets the reduction as resulting from a reduced surface density of active sites.

 References Archuleta, C. M., DeMott, P. J., and Kreidenweis, S. M.: Ice nucleation by surrogates for atmospheric mineral dust and mineral dust/sulfate particles at cirrus temperatures, Atmos. Chem. Phys., 5, 2617–2634, 2005. Cantrell, W. and Heymsfield, A.: Production of ice in tropospheric clouds – A review, B. Am. Meteorol. Soc., 86(6), 795–807, 2005. Connolly, P J., Möhler, O., Field, P. R., Saathoff, H., Burgess, R., Wagner, R., Choularton, T., and Gallagher, M.: Studies of heterogeneous freezing by three different desert dust samples, Atmos. Chem. Phys., 9, 2805–2824, 2009. Cziczo, D J., Murphy, D M., Hudson, P K., and Thomson, D S.: Single particle measurements of the chemical composition of cirrus ice residue during crystal-face, J. Geophys. Res.-Atmos., 109, D04201, doi:10.1029/2003JD004032, 2004. Cziczo, D J., Froyd, K D., Gallavardin, S J., Möhler, O., Benz, S., Saathoff, H., and Murphy, D M.: Deactivation of ice nuclei due to atmospherically relevant surface coatings, Environ. Res. Lett., 4(4),2009. 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, Proc. Natl. Acad. Sci. USA, 100(25), 14655–14660, 2003a. DeMott, P J., Sassen, K., Poellot, M R., Baumgardner, D., Rogers, D C., Brooks, S D., Prenni, A J., and Kreidenweis, S M.: African dust aerosols as atmospheric ice nuclei, Geophys. Res. Lett., 30(14), 1732, doi:10.1029/2003GL017410, 2003b. Durant, A J. and Shaw, R A.: Evaporation freezing by contact nucleation inside-out, Geophys. Res. Lett., 32, L20814, doi:10.1029/2005GL024175, 2005. 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, 2006. Findeisen, W.: Die kolloidmeteorologischen Vorgänge bei der Niederschlagsbildung, Meteorologische Zeitung, 55, 121–133, 1938. Fletcher, N H.: Active sites and ice crystal nucleation, J. Atmos. Sci., 26(6), 1266–1271, 1969. FLUENT: FLUENT 6 user's guide, FLUENT Inc., 2001. Hartmann, S., Niedermeier, D., Shaw, R. A., Wex, H., and Stratmann, F.: Immersion freezing studies at the leipzig Aerosol Cloud Interaction Simulator, in preparation, 2010. Hennig, T., Massling, A., Brechtel, F J., and Wiedensohler, A.: A tandem DMA for highly temperature-stabilized hygroscopic particle growth measurements between 90% and 98% relative humidity, J. Aerosol Sci., 36, 1210–1223, 2005. Hung, H M., Malinowski, A., and Martin, S T.: Kinetics of heterogeneous ice nucleation on the surfaces of mineral dust cores inserted into aqueous ammonium sulfate particles, J. Phys. Chem. A, 107(9), 1296–1306, 2003. Kärcher, B. and Lohmann, U.: A parameterization of cirrus cloud formation: Heterogeneous freezing, J. Geophys. Res.-Atmos., 108, 4402, doi:10.1029/2002JD003220, 2003. Knopf, D A. and Koop, T.: Heterogeneous nucleation of ice on surrogates of mineral dust, J. Geophys. Res.-Atmos., 111, D12201, doi:10.1029/2005JD006894, 2006. Knutson, E O. and Whitby, K T.: Aerosol classification by electric mobility: Apparatus, theory and applications, J. Aerosol Sci., 6, 443–451, 1975. Langham, E J. and Mason, B J.: The heterogeneous and homogeneous nucleation of supercooled water, Proc. R. Soc. London Ser. A, 247(1251), 493–504, 1958. Lasaga, A C.: Fundamental approaches in describing mineral dissolution and precipitation rates, in: Chemical Weathering Rates of Silicate Minerals, volume~31 of Reviews in Mineralogy, pages 23–86. Mineralogical Society America, Washington, USA, 1995. Lohmann, U.: Aerosol effects on clouds and climate, Space Sci. Rev., 125, 129–137, 2006. Marcolli, C., Gedamke, S., Peter, T., and Zobrist, B.: Efficiency of immersion mode ice nucleation on surrogates of mineral dust, Atmos. Chem. Phys., 7, 5081–5091, 2007. Megahed, K.: The Impact of Mineral Dust Aerosol Particles on Cloud Formation, Dissertation, Rheinischen Friedrich-Wilhelms-Universität Bonn, 2007. Mertes, S., Galgon, D., Schwirn, K., Nowak, A., Lehmann, K., Massling, A., Wiedensohler, A., and Wieprecht, W.: Evolution of particle concentration and size distribution observed upwind, inside and downwind hill cap clouds at connected flow conditions during FEBUKO, Atmos. Environ., 39, 4233–4245, 2005. Mertes, S., Verheggen, B., Walter, S., Connolly, P., Ebert, M., Schneider, J., Bower, K N., Cozic, J., Weinbruch, S., Baltensperger, U., and Weingartner, E.: Counterflow virtual impact or based collection of small ice particles in mixed-phase clouds for the physico-chemical characterization of tropospheric ice nuclei : Sampler description and first case study, Aerosol Sci. Technol., 48, 848–864, 2007. 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, 2006. Particle Dynamics: FPM User's Guide, www.particle-dynamics.de, Particle Dynamics GmbH, Leipzig, Germany, 2005. Prospero, J M.: Long-term measurements of the transport of African mineral dust to the southeastern United States: Implications for regional air quality, J. Geophys. Res.-Atmos., 104(D13), 15917–15927, 1999. Pruppacher, H R. and Klett, J D.: Microphysics of Clouds and Precipitation, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1997. Reitz, P., Schneider, J., Wex, H., Startmann, F., Niedermeier, D., Mildenberger, K., Covert, D., Spindler, C., Mentel, T F., Poulain, L., and Borrmann, S.: Detection of thin coatings on refractory particles with an aerodyne aerosol mass spectrometer and implications for laboratory studies of hygroscopic growth, CCN and IN activation, in preparation, 2010. Richardson, M S., DeMott, P J., Kreidenweis, S M., Cziczo, D J., Dunlea, E J., Jimenez, J L., Thomson, D S., Ashbaugh, L L., Borys, R D., Westphal, D L., Casuccio, G S., and Lersch, T L.: Measurements of heterogeneous ice nuclei in the western united states in springtime and their relation to aerosol characteristics, J. Geophys. Res.-Atmos., 112, D02209, doi:10.1029/2006JD007500, 2007. Roberts, G C. and Nenes, A.: A continuous-flow streamwise thermal-gradient CCN chamber for atmospheric measurements, Aerosol Sci. Technol., 39(3), 206–221, 2005. Rogers, R. and Yau, M.: A Short Course in Cloud Physics, volume~3, Butterworth Heinemann-An imprint of Elsevier, third edition, 1996. Sassen, K., DeMott, P J., Prospero, J M., and Poellot, M R.: Saharan dust storms and indirect aerosol effects on clouds: Crystal-face results, Geophys. Res. Lett., 30, 1633, doi:10.1029/2003GL017371, 2003. Seinfeld, J. and Pandis, S.: Atmospheric Chemistry and Physics From Air Pollution to Climate Change, Wiley-Interscience, 1998. Shaw, R A., Durant, A J., and Mi, Y.: Heterogeneous surface crystallization observed in undercooled water, J. Phys. Chem. B, 109, 9865–9868, 2005. Stratmann, F., Kiselev, A., Wurzler, S., Wendisch, M., Heintzenberg, J., Charlson, R J., Diehl, K., Wex, H., and Schmidt, S.: Laboratory studies and numerical simulations of cloud droplet formation under realistic supersaturation conditions, J. Atmos. Oceanic Technol., 21(6), 876–887, 2004. Vali, G.: Freezing rate due to heterogneous nucleation, J. Atmos. Sci., 51(13), 1843–1856, 1994. Vali, G.: Repeatability and randomness in heterogeneous freezing nucleation, Atmos. Chem. Phys., 8, 5017–5031, 2008. Wex, H., Clauss, T., Covert, D., Hallbauer, E., Hartmann, S., Kiselev, A., Mentel, T F., Mildenberger, K., Niedermeier, D., Poulain, L., Reitz, P., Schneider, J., Shaw, R., Spindler, C., and Stratmann, F.: Classifying coated and uncoated arizona test dust with respect to hygroscopic growth and activation, in preparation, 2010. Yuskiewicz, B A., Stratmann, F., Birmili, W., Wiedensohler, A., Swietlicki, E., Berg, O., and Zhou, J.: The effects of in-cloud mass production on atmospheric light scatter, Atmos. Res., 50, 265–288, 1999. Zobrist, B., Koop, T., Luo, B P., Marcolli, C., and Peter, T.: Heterogeneous ice nucleation rate coefficient of water droplets coated by a nonadecanol monolayer, J. Phys. Chem. C, 111(5), 2149–2155, 2007. Zobrist, B., Marcolli, C., Peter, T., and Koop, T.: Heterogeneous ice nucleation in aqueous solutions: the role of water activity, J. Phys. Chem. A, 112(17), 3965–3975, 2008. Zuberi, B., Bertram, A K., Cassa, C A., Molina, L T., and Molina, M J.: Heterogeneous nucleation of ice in (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>-H<sub>2</sub>O particles with mineral dust immersions, Geophys. Res. Lett., 29(10), 1504, doi:10.1029/2001GL014289, 2002.