• Bohren, C. F., and Huffman D. R. , 1983: Absorption and Scattering of Light by Small Particles. John Wiley and Sons, 530 pp.

  • Comstock, J. M., and Coauthors, 2007: An intercomparison of microphysical retrieval algorithms for upper-tropospheric ice clouds. Bull. Amer. Meteor. Soc., 88, 191204.

    • Search Google Scholar
    • Export Citation
  • DeVore, J. G., and Coauthors, 2009: Retrieving properties of thin clouds from solar aureole measurements. J. Atmos. Oceanic Technol., 26, 25312548.

    • Search Google Scholar
    • Export Citation
  • Heymsfield, A. J., and Platt C. M. R. , 1984: A parameterization of the particle size spectrum of ice clouds in terms of the ambient temperature and the ice water content. J. Atmos. Sci., 41, 846855.

    • Search Google Scholar
    • Export Citation
  • Holben, B. N., and Coauthors, 1998: AERONET—A federated instrument network and data archive for aerosol characterization. Remote Sens. Environ., 66, 116.

    • Search Google Scholar
    • Export Citation
  • Jackson, J. D., 1975: Classical Electrodynamics. 2nd ed. John Wiley and Sons, 848 pp.

  • Junge, C. E., 1955: The size distribution and aging of natural aerosols as determined from electrical and optical data on the atmosphere. J. Atmos. Sci., 12, 1325.

    • Search Google Scholar
    • Export Citation
  • Linskens, J. R., and Bohren C. F. , 1994: Appearance of the sun and the moon seen through clouds. Appl. Opt., 33, 47334740.

  • Liou, K. N., 2002: An Introduction to Atmospheric Radiation. 2nd ed. Academic Press, 583 pp.

  • Platt, C., 1997: A parameterization of the visible extinction coefficient of ice clouds in terms of the ice/water content. J. Atmos. Sci., 54, 20832098.

    • Search Google Scholar
    • Export Citation
  • Romanov, P., O’Neill N. , Royer A. , and McArthur B. , 1999: Simultaneous retrieval of aerosol refractive index and particle size distribution from ground-based measurements of direct and scattered solar radiation. Appl. Opt., 38, 73057320.

    • Search Google Scholar
    • Export Citation
  • Somerville, R. C. J., 2008: The Forgiving Air: Understanding Environmental Change. 2nd ed. Amer. Meteor. Soc., 202 pp.

  • Starr, D., 2010: NPP VIIRS atmosphere data products validation plan. [Available online at http://modis.gsfc.nasa.gov/sci_team/meetings/201001/presentations/atmos/starr.pdf.]

    • Search Google Scholar
    • Export Citation
  • Yang, P., Baum B. A. , Heymsfield A. J. , Hu Y. X. , Huang H.-L. , Tsay S.-C. , and Ackerman S. , 2003: Single-scattering properties of droxtals. J. Quant. Spectrosc. Radiat. Transfer, 79, 11591169.

    • Search Google Scholar
    • Export Citation
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Improved Normalization of the Size Distribution of Atmospheric Particles Retrieved from Aureole Measurements Using the Diffraction Approximation

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  • 1 Visidyne, Inc., Santa Barbara, California
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Abstract

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the solar disk radiance is replaced with one based on the aureole profile radiance itself. Retrievals involving model calculations for power-law distributions of water droplets show significant improvement using the new algorithm. Tests involving two empirical particle size distributions, one for cirrus and another for aerosols, also show improvement using the new normalization algorithm. Comparisons of the diffraction approximation algorithms with a numerical inversion algorithm found that the accuracy of the latter was higher for two different bimodal aerosol distributions. The role envisioned for the diffraction approximation is in estimating the size distribution of large particles in clouds and especially cirrus.

Corresponding author address: John DeVore, Visidyne, Inc., 429 Stanley Drive, Santa Barbara, CA 93105. E-mail: devore@visidyne.com

Abstract

This paper describes an improvement in the diffraction approximation used to retrieve the size distribution of atmospheric particles from solar aureole radiance measurements. Normalization using total optical thickness based on measurement of the solar disk radiance is replaced with one based on the aureole profile radiance itself. Retrievals involving model calculations for power-law distributions of water droplets show significant improvement using the new algorithm. Tests involving two empirical particle size distributions, one for cirrus and another for aerosols, also show improvement using the new normalization algorithm. Comparisons of the diffraction approximation algorithms with a numerical inversion algorithm found that the accuracy of the latter was higher for two different bimodal aerosol distributions. The role envisioned for the diffraction approximation is in estimating the size distribution of large particles in clouds and especially cirrus.

Corresponding author address: John DeVore, Visidyne, Inc., 429 Stanley Drive, Santa Barbara, CA 93105. E-mail: devore@visidyne.com
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