• Albrecht, B. A., R. P. Penc, and W. H. Schubert, 1985: An observational study of cloud-topped mixed layer. J. Atmos. Sci.,42, 800–822.

  • ——, C. W. Fairall, D. W. Thomson, and A. B. White, 1990: Surface-based remote sensing of the observed and the adiabatic liquid water content of stratocumulus clouds. Geophys. Res. Lett.,17, 89–92.

  • ——, S. Bretherton, D. Johnson, W. H. Schubert, and A. S. Frisch, 1995: The Atlantic Stratocumulus Transition Experiment—ASTEX. Bull. Amer. Meteor. Soc.,76, 889–904.

  • Chen, C., and W. R. Cotton, 1987: The physics of the marine stratocumulus-capped mixed layer. J. Atmos. Sci.,44, 2951–2977.

  • Chin, H.-N. S., 1994: The impact of the ice phase and radiation on a midlatitude squall line. J. Atmos. Sci.,51, 3320–3343.

  • ——, Q. Fu, M. M. Bradley, and C. R. Molenkamp, 1995: Modeling of a tropical squall line in two dimensions: Sensitivity to radiation and comparison with a midlatitude case. J. Atmos. Sci.,52, 3172–3193.

  • Chuang, C. C., J. E. Penner, K. E. Taylor, and A. S. Grossman, 1997:An assessment of the radiative effects of anthropogenic sulfate. J. Geophys. Res.,102, 3761–3778.

  • Clothiaux, E. E., and Coauthors, 1999: The Atmospheric Radiation Measurement program cloud radars: Operational modes. J. Atmos. Oceanic Technol.,16, 819–827.

  • Cotton, W. R., 1975: On parameterization of turbulent transport in cumulus clouds. J. Atmos. Sci.,32, 548–564.

  • Deardorff, J. W., 1980: Cloud top entrainment instability. J. Atmos. Sci.,37, 131–147.

  • Dong, X., T. P. Ackerman, E. E. Clothiaux, P. Pilewskie, and Y. Han, 1997: Microphysical and radiative properties of boundary stratiform clouds deduced from ground-based measurements. J. Geophys. Res.,102, 23 829–23 843.

  • Frisch, A. S., C. W. Fairall, and J. B. Snider, 1995: Measurements of stratus cloud and drizzle parameters in ASTEX with a Kα-band Doppler radar and a microwave radiometer. J. Atmos. Sci.,52, 2788–2799.

  • Fu, Q., and K.-N. Liou, 1993: Parameterization of the radiative properties of cirrus clouds. J. Atmos. Sci.,50, 2008–2025.

  • ——, ——, M. C. Cribb, T. P. Charlock, and A. Grossman, 1997: On multiple scattering parameterization in thermal infrared radiation transfer. J. Atmos. Sci.,54, 2799–2812.

  • ——, M. C. Cribb, H. W. Barker, S. K. Krueger, and A. Grossman, 2000: Cloud geometry effects on atmospheric solar absorption. J. Atmos. Sci.,57, 1153–1168.

  • Han, Y., and E. R. Westwater, 1995: Remote sensing of tropospheric water vapor and cloud liquid water by integrated ground-based sensors. J. Atmos. Oceanic Technol.,12, 1050–1059.

  • Hartmann, D. L., M. E. Ocker-Bell, and M. L. Michelsen, 1992: The effects of cloud type on earth’s energy balance: Global analysis. J. Climate,5, 1281–1304.

  • Ishizaka, Y., Y. Kurahashi, and H. Tsuruta, 1995: Microphysical properties of winter stratiform clouds over the southwest island area in Japan. J. Meteor. Soc. Japan,73, 1137–1151.

  • Leaitch, W. R., G. A. Issac, J. W. Strapp, C. M., Banic, and H. A. Wiebe, 1992: The relationship between cloud droplet number concentrations and anthropogenic pollution: Observations and climatic implications. J. Geophys. Res.,97, 2463–2474.

  • Liao, L., and K. Sassen, 1994: Investigation of relationships between Ka-band radar reflectivity and ice and liquid water contents. Atmos. Res.,34, 231–248.

  • Liou, K.-N., 1992: Radiation and Cloud Processes in the Atmosphere. Oxford University Press, 487 pp.

  • ——, and G. D. Wittman, 1979: Parameterization of the radiative properties of clouds. J. Atmos. Sci.,36, 1261–1273.

  • Manabe, S., and R. J. Stouffer, 1980: Sensitivity of a global climate model to an increase of CO2 concentration in the atmosphere. J. Geophys. Res.,85, 5529–5554.

  • Martin, G. M., and D. W. Johnson, 1992: The measurements and parameterization of effective radius of droplets in stratocumulus clouds. Proc. 11th Int. Conf. on Clouds and Precipitation, Vol. 1, Montreal, PQ, Canada, International Commission on Clouds and Precipitation and International Association of Meteorology and Atmospheric Physics, 158–161,.

  • ——, ——, and A. Spice, 1994: The measurement and parameterization of effective radius of droplets in warm stratocumulus clouds. J. Atmos. Sci.,51, 1823–1842.

  • Nicholls, S., 1984: The dynamics of stratocumulus: Aircraft observations and comparisons with a mixed layer model. Quart. J. Roy. Meteor. Soc.,110, 783–820.

  • ——, and J. Leighton, 1986: An observational study of the structure of stratiform cloud sheets: Part I. Structure. Quart. J. Roy. Meteor. Soc.,112, 431–460.

  • Noonkester, V. R., 1984: Droplet spectra observed in marine stratus cloud layers. J. Atmos. Sci.,41, 829–845.

  • Paluch, I. R., C. A. Knight, and L. J. Miller, 1996: Cloud liquid water and radar reflectivity of nonprecipitating cumulus clouds. J. Atmos. Sci.,53, 1587–1603.

  • Politovich, M. K., B. B. Stankov, and B. E. Martner, 1995: Determination of liquid water altitudes using combined remote sensors. J. Appl. Meteor.,34, 2060–2075.

  • Ramanathan, V., R. D. Cess, E. F. Harrison, P. Minnis, B. R. Barkstrom, E. Ahmad, and D. L. Hartmann, 1989: Cloud-radiative forcing and climate: Results from the Earth Radiation Budget Experiment. Science,243, 57–63.

  • Rogers, D. P., and J. W. Telford, 1986: Metastable tops. Quart. J. Roy. Meteor. Soc.,112, 481–500.

  • Slingo, A., 1989: A GCM parameterization for the shortwave radiative properties of water clouds. J. Atmos. Sci.,46, 1419–1427.

  • ——, S. Nicholls, and J. Schmetz, 1982: Aircraft observations of marine stratus during JASIN. Quart. J. Roy. Meteor. Soc.,108, 833–856.

  • Stephens, G. L., 1978: Radiation profiles in extended water clouds. Part II: Parameterization schemes. J. Atmos. Sci.,35, 2123–2132.

  • ——, 1984: The parameterization of radiation from numerical weather prediction and climate models. Mon. Wea. Rev.,112, 826–867.

  • Twomey, S., M. Piepgrass, and T. L. Wolfe, 1984: An assessment of the impact of pollution on global cloud albedo. Tellus,36B, 356–366.

  • Washington, W. M., and G. A. Meehl, 1984: Seasonal cycle experiment on the climate sensitivity due to a doubling of CO2 with an atmospheric general circulation model coupled to a simple mixed-layer ocean model. J. Geophys. Res.,89, 9475–9503.

  • Westwater, E. R., 1978: The accuracy of water vapor and cloud liquid determination by dual-frequency ground-based microwave radiometry. Radio Sci.,13, 677–685.

  • Wong, T., G. L. Stephens, P W. Stackhouse Jr., and F. P. J. Valero, 1993: The radiative budgets of a tropical mesoscale convective system during EMEX-STEP-AMEX experiment. II: Model results. J. Geophys. Res.,98, 8695–8711.

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A Microphysical Retrieval Scheme for Continental Low-Level Stratiform Clouds: Impacts of the Subadiabatic Character on Microphysical Properties and Radiation Budgets

Hung-Neng S. ChinAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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Daniel J. RodriguezAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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Richard T. CederwallAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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Catherine C. ChuangAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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Allen S. GrossmanAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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John J. YioAtmospheric Science Division, Lawrence Livermore National Laboratory, Livermore, California

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Qiang FuAtmospheric Sciences Program, Dalhousie University, Halifax, Nova Scotia, Canada

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Mark A. MillerDivision of Applied Science, Brookhaven National Laboratory, Upton, New York

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Abstract

Using measurements from the Department of Energy’s Atmospheric Radiation Measurement Program, a modified ground-based remote sensing technique is developed and evaluated to study the impacts of the subadiabatic character of continental low-level stratiform clouds on microphysical properties and radiation budgets. Airborne measurements and millimeter-wavelength cloud radar data are used to validate retrieved microphysical properties of three stratus cloud systems occurring in the April 1994 and 1997 intensive observation periods at the Southern Great Plains site.

The addition of the observed cloud-top height into the Han and Westwater retrieval scheme eliminates the need to invoke the adiabatic assumption. Thus, the retrieved liquid water content (LWC) profile is represented as the product of an adiabatic LWC profile and a weighting function. Based on in situ measurements, two types of weighting functions are considered in this study: one is associated with a subadiabatic condition involving cloud-top entrainment mixing alone (type I) and the other accounts for both cloud-top entrainment mixing and drizzle effects (type II). The adiabatic cloud depth ratio (ACDR), defined as the ratio of the actual cloud depth to the one derived from the adiabatic assumption, is found to be a useful parameter for classifying the subadiabatic character of low-level stratiform clouds. The type I weighting function only exists in the lower ACDR regime, while the type II profile can appear for any adiabatic cloud depth ratio.

Results indicate that the subadiabatic character of low-level stratiform clouds has substantial impacts on radiative energy budgets, especially those in the shortwave, via the retrieved LWC distribution and its related effective radius profile of liquid water. Results also show that this subadiabatic character can act to stabilize the cloud deck by reducing the in-cloud radiative heating/cooling contrast. As a whole, these impacts strengthen as the subadiabatic character of low-level stratiform clouds increases.

Corresponding author address: Dr. Hung-Neng S. Chin, Lawrence Livermore National Laboratory, P.O. Box 808 (L-103), Livermore, CA 94551.

Email: chin2@llnl.gov

Abstract

Using measurements from the Department of Energy’s Atmospheric Radiation Measurement Program, a modified ground-based remote sensing technique is developed and evaluated to study the impacts of the subadiabatic character of continental low-level stratiform clouds on microphysical properties and radiation budgets. Airborne measurements and millimeter-wavelength cloud radar data are used to validate retrieved microphysical properties of three stratus cloud systems occurring in the April 1994 and 1997 intensive observation periods at the Southern Great Plains site.

The addition of the observed cloud-top height into the Han and Westwater retrieval scheme eliminates the need to invoke the adiabatic assumption. Thus, the retrieved liquid water content (LWC) profile is represented as the product of an adiabatic LWC profile and a weighting function. Based on in situ measurements, two types of weighting functions are considered in this study: one is associated with a subadiabatic condition involving cloud-top entrainment mixing alone (type I) and the other accounts for both cloud-top entrainment mixing and drizzle effects (type II). The adiabatic cloud depth ratio (ACDR), defined as the ratio of the actual cloud depth to the one derived from the adiabatic assumption, is found to be a useful parameter for classifying the subadiabatic character of low-level stratiform clouds. The type I weighting function only exists in the lower ACDR regime, while the type II profile can appear for any adiabatic cloud depth ratio.

Results indicate that the subadiabatic character of low-level stratiform clouds has substantial impacts on radiative energy budgets, especially those in the shortwave, via the retrieved LWC distribution and its related effective radius profile of liquid water. Results also show that this subadiabatic character can act to stabilize the cloud deck by reducing the in-cloud radiative heating/cooling contrast. As a whole, these impacts strengthen as the subadiabatic character of low-level stratiform clouds increases.

Corresponding author address: Dr. Hung-Neng S. Chin, Lawrence Livermore National Laboratory, P.O. Box 808 (L-103), Livermore, CA 94551.

Email: chin2@llnl.gov

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