• Arthur, D. K., S. Lasher-Trapp, A. Abdel-Haleem, N. Klosterman, and D. S. Ebert, 2010: A new three-dimensional visualization system for combining aircraft and radar data and its application to RICO observations. J. Atmos. Oceanic Technol., 27, 811828.

    • Search Google Scholar
    • Export Citation
  • Bohren, C. F., and R. Huffman, 1983: Absorption and Scattering of Light by Small Particles. Wiley, 544 pp.

  • Bower, K. N., and Coauthors, 1997: Observations and modeling of the processing of aerosol by a hill cap cloud. Atmos. Environ., 31, 25272543.

    • Search Google Scholar
    • Export Citation
  • Buck, A. L., 1976: The variable-path Lyman-Alpha hygrometer and its operating characteristics. Bull. Amer. Meteor. Soc., 57, 11131118.

    • Search Google Scholar
    • Export Citation
  • Cautenet, S., and B. Lefeivre, 1994: Contrasting behavior of gas and aerosol scavenging in convective rain: A numerical and experimental study in the African equatorial forest. J. Geophys. Res., 99 (D6), 13 01313 024.

    • Search Google Scholar
    • Export Citation
  • Charlson, R. J., A. S. Ackerman, F. A.-M. Bender, T. L. Anderson, and Z. Liu, 2007: On the climate forcing consequences of the albedo continuum between cloudy and clear air, Tellus,59B, 715–727, doi:10.1111/j.1600-0889.2007.00297.x.

    • Search Google Scholar
    • Export Citation
  • Coelho, A. A., J.-L. Brenguier, and T. Perrin, 2005a: Droplet spectra measurements with the FSSP-100. Part I: Low droplet concentration measurements. J. Atmos. Oceanic Technol., 22, 17481755.

    • Search Google Scholar
    • Export Citation
  • Coelho, A. A., J.-L. Brenguier, and T. Perrin, 2005b: Droplet spectra measurements with the FSSP-100. Part II: Coincidence effects. J. Atmos. Oceanic Technol., 22, 17561761.

    • Search Google Scholar
    • Export Citation
  • Collins, D. R., and Coauthors, 2000: In situ aerosol-size distributions and clear-column radiative closure during ACE-2. Tellus, 52B, 498525.

    • Search Google Scholar
    • Export Citation
  • Davison, J. L., R. M. Rauber, L. Di Girolamo, and M. A. Lemone, 2013a: A revised conceptual model of the tropical marine boundary layer. Part I: Statistical characterization of the variability inherent in the wintertime trade wind regime over the western tropical Atlantic. J. Atmos. Sci., 70, 30053024.

    • Search Google Scholar
    • Export Citation
  • Davison, J. L., R. M. Rauber, and L. Di Girolamo, 2013b: A revised conceptual model of the tropical marine boundary layer. Part II: Detecting relative humidity layers using Bragg scattering from S-band radar. J. Atmos. Sci., 70, 30253046.

    • Search Google Scholar
    • Export Citation
  • Davison, J. L., R. M. Rauber, L. Di Girolamo, and M. A. Lemone, 2013c: A revised conceptual model of the tropical marine boundary layer. Part III: Bragg scattering layer statistical properties. J. Atmos. Sci., 70, 30473062.

    • Search Google Scholar
    • Export Citation
  • Easter, R. C., and P. V. Hobbs, 1974: The formation of sulfates and the enhancement of cloud condensation nuclei in clouds. J. Atmos. Sci., 31, 15861594.

    • Search Google Scholar
    • Export Citation
  • Fletcher, N. H., 1966: The Physics of Rainclouds. Cambridge University Press, 390 pp.

  • Flossmann, A. I., 1998: Interaction of aerosol particles and clouds. J. Atmos. Sci., 55, 879887.

  • Flossmann, A. I., H. R. Pruppacher, and J. H. Topalian, 1987: A theoretical study of the wet removal of atmospheric pollutants. Part II: The uptake and redistribution of (NH4)2SO4 particles and SO2 gas simultaneously scavenged by growing cloud drops. J. Atmos. Sci., 44, 29122923.

    • Search Google Scholar
    • Export Citation
  • Friehe, C. A., R. L. Grossman, and Y. Pann, 1986: Calibration of an airborne Lyman-alpha hygrometer and measurement of water vapor flux using a thermoelectric hygrometer. J. Atmos. Oceanic Technol., 3, 299304.

    • Search Google Scholar
    • Export Citation
  • Gerber, H., 1994: New microphysics sensor for aircraft use. Atmos. Res., 31, 235252.

  • Hegg, D. A., and P. V. Hobbs, 1982: Measurement of the sulphate production in natural clouds. Atmos. Environ., 16, 26632668.

  • Hess, M., P. Koepke, and I. Schult, 1998: Optical properties of aerosols and clouds: The software package OPAC. Bull. Amer. Meteor. Soc., 79, 831844.

    • Search Google Scholar
    • Export Citation
  • Heus, T., and H. J. J. Jonker, 2008: Subsiding shells around shallow cumulus clouds. J. Atmos. Sci., 65, 10031018.

  • Heus, T., C. F. J. Pols, H. J. J. Jonker, H. E. A. Van den Akker, and D. H. Lenschow, 2009: Observational validation of the compensating mass flux through the shell around cumulus clouds. Quart. J. Roy. Meteor. Soc., 135, 101112, doi:10.1002/qj.358.

    • Search Google Scholar
    • Export Citation
  • Higurashi, A., and T. Nakajima, 1999: Development of a two-channel aerosol retrieval algorithm on a global scale using NOAA AVHRR. J. Atmos. Sci., 56, 924941.

    • Search Google Scholar
    • Export Citation
  • Hoppel, W. A., G. M. Frick, and R. E. Larson, 1986: Effect of nonprecipitating clouds on the aerosol size distribution in the marine boundary layer. Geophys. Res. Lett., 13, 125128.

    • Search Google Scholar
    • Export Citation
  • Hoppel, W. A., G. M. Fitzgerald, G. M. Frick, R. E. Larson, and E. J. Mack, 1990: Aerosol size distributions and optical properties found in the marine boundary layer over the Atlantic Ocean. J. Geophys. Res., 95 (D4), 36593686.

    • Search Google Scholar
    • Export Citation
  • Hoppel, W. A., G. M. Frick, G. M. Fitzgerald, and R. E. Larson, 1994: Marine boundary layer measurements of new particle formation and the effect which nonprecipitating clouds have on the aerosol size distribution. J. Geophys. Res., 99 (D7), 14 44314 459.

    • Search Google Scholar
    • Export Citation
  • Hutchison, K. D., B. D. Iisager, T. J. Kopp, and J. M. Jackson, 2008: Distinguishing aerosols from clouds in global, multispectral satellite data with automated cloud classification algorithms. J. Atmos. Oceanic Technol., 25, 501518.

    • Search Google Scholar
    • Export Citation
  • King, W. D., D. A. Parkin, and R. J. Handsworth, 1978: A hot-wire liquid water device having fully calculable response characteristics. J. Appl. Meteor., 17, 18091813.

    • Search Google Scholar
    • Export Citation
  • Kleinman, L. I., and P. H. Daum, 1991: Vertical distribution of aerosol particles, water vapor, and insoluble trace gases in convectively mixed air. J. Geophys. Res., 96, 9911005.

    • Search Google Scholar
    • Export Citation
  • Köhler, H., 1936: The nucleus in and the growth of hygroscopic droplets. Trans. Faraday Soc., 32, 11521161.

  • Koren, I., L. A. Remer, Y. J. Kaufman, Y. Rudich, and J. V. Martins, 2007: On the twilight zone between clouds and aerosols. Geophys. Res. Lett., 34, L08805, doi:10.1029/2007GL029253.

    • Search Google Scholar
    • Export Citation
  • Laird, N. F., 2005: Humidity halos surrounding small cumulus clouds in a tropical environment. J. Atmos. Sci., 62, 34203425.

  • Leaitch, W. R., 1996: Observations pertaining to the effect of chemical transformation in cloud on the anthropogenic aerosol size distribution. Aerosol Sci. Technol., 25, 157173.

    • Search Google Scholar
    • Export Citation
  • Liu, P. S. K., W. R. Leaitch, J. W. Strapp, and M. A. Wasey, 1992: Response of particle measurement systems airborne ASASP and PCASP to NaCl and latex particles. Aerosol Sci. Technol., 16, 8395.

    • Search Google Scholar
    • Export Citation
  • Loeb, N. G., and S. Kato, 2002: Top-of-atmosphere direct radiative effect of aerosols over the tropical oceans from the Clouds and the Earth's Radiant Energy System (CERES) satellite instrument. J. Climate, 15, 14741484.

    • Search Google Scholar
    • Export Citation
  • Loeb, N. G., and N. Manalo-Smith, 2005: Top-of-atmosphere direct radiative effect of aerosols over global oceans from merged CERES and MODIS observation. J. Climate, 18, 35063526.

    • Search Google Scholar
    • Export Citation
  • Lu, M.-L., J. Wang, A. Freedman, H. H. Jonsson, R. C. Flagan, R. A. McClatchey, and J. H. Seinfeld, 2003: Analysis of humidity halos around trade wind cumulus clouds. J. Atmos. Sci., 60, 10411059.

    • Search Google Scholar
    • Export Citation
  • Marshak, A., G. Wen, J. A. Coakley Jr., L. A. Remer, N. G. Loeb, and R. F. Cahalan, 2008: A simple model for the cloud adjacency effect and the apparent bluing of aerosols near clouds. J. Geophys. Res., 113, D14S17, doi:10.1029/2007JD009196.

    • Search Google Scholar
    • Export Citation
  • Martins, J. V., D. Tanré, L. Remer, Y. Kaufman, S. Mattoo, and R. Levy, 2002: MODIS cloud screening for remote sensing of aerosols over oceans using spatial variability. Geophys. Res. Lett., 29, 8009, doi:10.1029/2001GL013252.

    • Search Google Scholar
    • Export Citation
  • Minor, H. A., R. M. Rauber, S. Göke, and L. Di Girolamo, 2011: Trade wind cloud evolution observed by polarization radar: Relationship to giant condensation nuclei concentrations and cloud organization. J. Atmos. Sci., 68, 10751096.

    • Search Google Scholar
    • Export Citation
  • Nagel, D., U. Maixner, W. Strapp, and M. Wasey, 2007: Advancements in techniques for calibration and characterization of in situ optical particle measuring probes, and applications to the FSSP-100 probe. J. Atmos. Oceanic Technol., 24, 745760.

    • Search Google Scholar
    • Export Citation
  • Nilsson, B., 1979: Meteorological influence on aerosol extinction in the 0.2-40 μm wavelength range. Appl. Opt., 18, 34573473.

  • Nuijens, L., B. Stevens, and A. P. Siebesma, 2009: The environment of precipitating shallow cumulus convection. J. Atmos. Sci., 66, 19621979.

    • Search Google Scholar
    • Export Citation
  • Perry, K. D., and P. V. Hobbs, 1994: Further evidence for particle nucleation in clear air adjacent to marine cumulus clouds. J. Geophys. Res., 99, 22 80322 818.

    • Search Google Scholar
    • Export Citation
  • Perry, K. D., and P. V. Hobbs, 1996: Influences of isolated cumulus clouds on the humidity of their surroundings. J. Atmos. Sci., 53, 159174.

    • Search Google Scholar
    • Export Citation
  • Peter, J. R., S. T. Siems, J. B. Jensen, J. L. Gras, and J. M. Hacker, 2006: Prediction and observation of cloud processing of the aerosol size distribution by a band of cumulus. Quart. J. Roy. Meteor. Soc., 132, 845863.

    • Search Google Scholar
    • Export Citation
  • Peter, J. R., A. M. Blyth, B. Brooks, J. B. McQuaid, J. J. N. Lingard, and M. H. Smith, 2008: On the composition of Caribbean maritime aerosol particles measured during RICO. Quart. J. Roy. Meteor. Soc., 134, 10591063.

    • Search Google Scholar
    • Export Citation
  • Petters, M. D., and S. M. Kreidenweis, 2007: A single parameter representation of hygroscopic growth and cloud condensation nucleus activity. Atmos. Chem. Phys., 7, 19611971, doi:10.5194/acp-7-1961-2007.

    • Search Google Scholar
    • Export Citation
  • Pruppacher, H. R., and J. D. Klett, 1997: Microphysics of Clouds and Precipitation. 2nd ed. Kluwer, 954 pp.

  • Radke, L. F., and P. V. Hobbs, 1991: Humidity and particle fields around some small cumulus clouds. J. Atmos. Sci., 48, 11901193.

  • Rauber, R. M., and Coauthors, 2007: Rain in shallow cumulus over the ocean: The RICO campaign. Bull. Amer. Meteor. Soc., 88, 19121928.

    • Search Google Scholar
    • Export Citation
  • Redemann, J., Q. Zhang, P. B. Russell, J. M. Livingston, and L. A. Remer, 2009: Case studies of aerosol remote sensing in the vicinity of clouds. J. Geophys. Res., 114, D06209, doi:10.1029/2008JD010774.

    • Search Google Scholar
    • Export Citation
  • Reiche, C. K. H., and S. G. Lasher-Trapp, 2010: The minor importance of giant aerosol to precipitation development within small trade wind cumuli observed during RICO. Atmos. Res., 95, 386399.

    • Search Google Scholar
    • Export Citation
  • Remer, L. A., and Y. J. Kaufman, 2006: Aerosol direct radiative effect at the top of the atmosphere over cloud free ocean derived from four years of MODIS data. Atmos. Chem. Phys., 6, 237253.

    • Search Google Scholar
    • Export Citation
  • Rodhe, H., 1983 Precipitation scavenging and tropospheric mixing. Precipitation Scavenging, Dry Deposition and Resuspension, H. R. Pruppacher, R. G. Semonin, and W. G. N. Slinn, Eds., Elsevier, 719–730.

  • Rodts, S. M. A., P. G. Duynkerke, and H. J. J. Jonker, 2003: Size distributions and dynamical properties of shallow cumulus clouds from aircraft observations and satellite data. J. Atmos. Sci., 60, 18951912.

    • Search Google Scholar
    • Export Citation
  • Roelofs, G. J., and V. Kamphuis, 2009: Cloud processing, cloud evaporation, and the Angström exponent. Atmos. Chem. Phys., 9, 7180.

  • Rogers, R. R., and M. K. Yau, 1989: A Short Course in Cloud Physics. 3rd ed. Pergamon, 227 pp.

  • Schanot, A. J., 1987: Evaluation of the uses and limitations of lyman-alpha hygrometer as an operational airborne humidity sensor. Preprints, Sixth Symp. on Meteorological Observations and Instrumentation, New Orleans, LA, Amer. Meteor. Soc., 257260.

  • Schanot, A. J., and P. Spyers-Duran, 1987: Airborne intercomparison of three hygrometers. Preprints, Sixth Symp. on Meteorological Observations and Instrumentation, New Orleans, LA, Amer. Meteor. Soc., 209212.

  • Sekiguchi, M., T. Nakajima, K. Suzuki, K. Kawamoto, A. Higurashi, D. Rosenfeld, I. Sano, and S. Mukai, 2003: A study of the direct and indirect effects of aerosols using global satellite data sets of aerosol and cloud parameters. J. Geophys. Res., 108, 4699, doi:10.1029/2002JD003359.

    • Search Google Scholar
    • Export Citation
  • Snider, J. R., and M. D. Petters, 2008: Optical particle counter measurement of marine aerosol hygroscopic growth. Atmos. Chem. Phys., 8, 19491962.

    • Search Google Scholar
    • Export Citation
  • Snodgrass, E. R., L. Di Girolamo, and R. M. Rauber, 2009: Precipitation characteristics of trade wind clouds during RICO derived from radar, satellite, and aircraft measurements. J. Appl. Meteor. Climatol., 48, 464483.

    • Search Google Scholar
    • Export Citation
  • Strapp, J. W., W. R. Leaitch, and P. S. K. Liu, 1992: Hydrated and dried aerosol-size-distribution measurements from the Particle Measuring Systems FSSP-300 probe and the deiced PCASP-100X Probe. J. Atmos. Oceanic Technol., 9, 548555.

    • Search Google Scholar
    • Export Citation
  • Tackett, J. L., 2009: Aerosol spatial variability in the vicinity of marine boundary layer clouds observed by satellite-based lidar, M.S. thesis, Department of Atmospheric Science, University of Illinois at Urbana–Champaign, 232 pp.

  • Tackett, J. L., and L. Di Girolamo, 2009: Enhanced aerosol backscatter adjacent to tropical trade wind clouds revealed by satellite-based lidar. Geophys. Res. Lett., 36, L14804, doi:10.1029/2009GL039264.

    • Search Google Scholar
    • Export Citation
  • Twohy, C. H., 1991: Airborne condensation nucleus counter user's guide. National Center for Atmospheric Research Tech. Note NCAR/TN 356+EDD, 21 pp. [Available from the National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO.]

  • Twohy, C. H., J. A. Coakley, and W. R. Tahnk, 2009: Effect of changes in relative humidity on aerosol scattering near clouds. J. Geophys. Res., 114, D05205, doi:10.1029/2008JD010991.

    • Search Google Scholar
    • Export Citation
  • Vidaurre, G., J. Hallett, and D. C. Rogers, 2011: Airborne measurement of liquid and total water content. J. Atmos. Oceanic Technol., 28, 10881103.

    • Search Google Scholar
    • Export Citation
  • Wang, Y., and B. Geerts, 2010: Humidity variations across the edge of trade wind cumuli: Observations and dynamic implications. Atmos. Res., 97, 144156.

    • Search Google Scholar
    • Export Citation
  • Wang, Y., B. Geerts, and J. French, 2009: Dynamics of the cumulus cloud margin: An observational study. J. Atmos. Sci., 66, 36603677.

    • Search Google Scholar
    • Export Citation
  • Wen, G., A. Marshak, R. F. Cahalan, L. A. Remer, and R. G. Kleidman, 2007: 3D aerosol-cloud radiative interaction observed in collocated MODIS and ASTER images of cumulus cloud fields. J. Geophys. Res., 112, D13204, doi:10.1029/2006JD008267.

    • Search Google Scholar
    • Export Citation
  • Wielicki, B. A., and R. M. Welch, 1986: Cumulus cloud properties derived using Landsat satellite data. J. Climate Appl. Meteor., 25, 261276.

    • Search Google Scholar
    • Export Citation
  • Yang, Y., and L. Di Girolamo, 2008: Impacts of 3-D radiative effects on satellite cloud detection and their consequences on cloud fraction and aerosol optical depth retrievals. J. Geophys. Res., 113, D04213, doi:10.1029/2007JD009095.

    • Search Google Scholar
    • Export Citation
  • Yin, Y., K. S. Carslaw, and G. Feingold, 2005: Vertical transport and processing of aerosols in a mixed-phase cloud and the feedback on cloud development. Quart. J. Roy. Meteor. Soc., 131, 221245.

    • Search Google Scholar
    • Export Citation
  • Zhao, G., and L. Di Girolamo, 2007: Statistics on the macrophysical properties of trade wind cumuli over the tropical western Atlantic. J. Geophys. Res., 112, D10204, doi:10.1029/2006JD007371.

    • Search Google Scholar
    • Export Citation
  • Zuidema, P., R. J. Hill, L. Bariteau, R. Rilling, C. Fairall, W. A. Brewer, B. Albrecht, and J. Hare, 2012: On trade wind cumulus cold pools. J. Atmos. Sci., 69, 258280.

    • Search Google Scholar
    • Export Citation
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Aerosol Size Distribution, Particle Concentration, and Optical Property Variability near Caribbean Trade Cumulus Clouds: Isolating Effects of Vertical Transport and Cloud Processing from Humidification Using Aircraft Measurements

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  • 1 Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois
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Abstract

This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical properties are examined as a function of altitude and distance from cloud, at ambient relative humidity (RH) and adjusted to a constant RH to isolate effects of humidification from other processes.

The cloud humidity halo extended about 1500–2000 m from the cloud edge, with no clear altitude dependence on horizontal extent over an altitude range of 600–1700 m. The combined effects of vertical transport of aerosol by clouds and cloud processing contributed to the modification of aerosol size distributions within the clouds' humidity halos, particularly close to the cloud boundaries. Backscatter at 532 nm, calculated from the aerosol properties, exhibited no distinguishable trend with altitude within 400 m of cloud edges, increased toward lower altitudes beyond 400 m, and decreased away from cloud boundaries at all altitudes. The mean aerosol diameter was found to rapidly decline from 0.8 to 0.4 μm from near the cloud boundary to the boundary of the humidity halo. Aerosol optical depth at 532 nm within the layer between 600 and 1700 m increased near exponentially from 0.02 to 0.2 toward the cloud boundaries within the humidity halo. These trends agreed qualitatively with past space-based lidar measurements of trade wind cloud margins, although quantitative differences were noted that likely arose from different sampling strategies and other factors.

Corresponding author address: Robert M. Rauber, Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, 105 S. Gregory St., Urbana, IL 61801. E-mail: r-rauber@illinois.edu

Abstract

This paper examines the effect of trade wind cumulus clouds on aerosol properties in the near-cloud environment using data from the Rain in Cumulus over the Ocean (RICO) campaign. Aerosol size distributions, particle concentrations, and optical properties are examined as a function of altitude and distance from cloud, at ambient relative humidity (RH) and adjusted to a constant RH to isolate effects of humidification from other processes.

The cloud humidity halo extended about 1500–2000 m from the cloud edge, with no clear altitude dependence on horizontal extent over an altitude range of 600–1700 m. The combined effects of vertical transport of aerosol by clouds and cloud processing contributed to the modification of aerosol size distributions within the clouds' humidity halos, particularly close to the cloud boundaries. Backscatter at 532 nm, calculated from the aerosol properties, exhibited no distinguishable trend with altitude within 400 m of cloud edges, increased toward lower altitudes beyond 400 m, and decreased away from cloud boundaries at all altitudes. The mean aerosol diameter was found to rapidly decline from 0.8 to 0.4 μm from near the cloud boundary to the boundary of the humidity halo. Aerosol optical depth at 532 nm within the layer between 600 and 1700 m increased near exponentially from 0.02 to 0.2 toward the cloud boundaries within the humidity halo. These trends agreed qualitatively with past space-based lidar measurements of trade wind cloud margins, although quantitative differences were noted that likely arose from different sampling strategies and other factors.

Corresponding author address: Robert M. Rauber, Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, 105 S. Gregory St., Urbana, IL 61801. E-mail: r-rauber@illinois.edu
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