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Applied Optics

Applied Optics


  • Vol. 25, Iss. 15 — Aug. 1, 1986
  • pp: 2499–2505

Backscatter and extinction measurements in cloud and drizzle at CO2 laser wavelengths

S. G. Jennings  »View Author Affiliations

Applied Optics, Vol. 25, Issue 15, pp. 2499-2505 (1986)

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The backscatter and extinction of laboratory generated cloud and drizzle sized drops have been measured at CO2 laser wavelengths (predominately at λ = 10.591 μm). Measurements of volume backscatter coefficient σb and volume extinction coefficient σe for laboratory cloud of predominantly <20-μm radius droplets are dependent on the form of the size distribution in agreement with numerical prediction. For drops of ⪞20 μm at λ = 10.591 μm the relation between σe and σb has the appealingly simple size distribution independent form of σe/σb = 8π/G, G = ( n - 1 ) 2 + k 2 ( n + 1 ) 2 + k 2 is the asymptotic value of the backscatter gain, where n and k are the real and imaginary indices of refraction. The linear relation is in good agreement with extinction and backscatter measurements made on laboratory generated drizzle sized drops (r > 20 μm). This suggests that the extinction coefficient at CO2 laser wavelengths could be inferred from lidar backscatter return signals without requiring knowledge of the size distribution for drizzle and spherical precipitation sized water drops.

© 1986 Optical Society of America

Original Manuscript: January 11, 1986
Published: August 1, 1986

S. G. Jennings, "Backscatter and extinction measurements in cloud and drizzle at CO2 laser wavelengths," Appl. Opt. 25, 2499-2505 (1986)

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  1. J. D. Klett, “Stable Analytical Inversion Solution for Processing Lidar Returns,” Appl. Opt. 20, 211 (1981).
  2. S. Twomey, H. B. Howell, “The Relative Merit of White and Monochromatic Light for the Determination of Visibility by Backscattering Measurements,” Appl. Opt. 4, 501 (1965).
  3. L. W. Carrier, G. A. Cato, K. J. von Essen, “The Backscattering and Extinction of Visible and Infrared Radiation by Selected Major Cloud Models,” Appl. Opt. 6, 1209 (1967).
  4. D. B. Rensch, R. K. Long, “Comparative Studies of Extinction and Backscattering by Aerosols, Fog, and Rain at 10.6 μm and 0.63 μm,” Appl. Opt. 9, 1563 (1970).
  5. R. G. Pinnick, S. G. Jennings, P. Chylek, C. Ham, W. T. Grandy, “Backscatter and Extinction in Water Clouds,” J. Geophys. Res. 88, 6787 (1983).
  6. V. E. Derr, “Estimation of the Extinction Coefficient of Clouds from Multiwavelength Lidar Backscatter Measurements,” Appl. Opt. 19, 2310 (1980).
  7. J. A. Curcio, G. L. Knestrick, “Correlation of Atmospheric Transmission with Backscattering,” J. Opt. Soc. Am. 48, 686 (1958).
  8. H. Vogt, “Visibility Measurement Using Backscattered Light,” J. Atmos. Sci. 25, 912 (1968).
  9. R. H. Dubinsky, A. I. Carswell, S. R. Pal, “Determination of Cloud Microphysical Properties by Laser Backscattering and Extinction Measurements,” Appl. Opt. 24, 1614 (1985).
  10. F. F. Hall, “Atmospheric Infrared Backscatter: Summary of Present Knowledge and Recommendations for Future Work,” NOAA Tech. Memo. ERL WPL-110, Wave Propagation Laboratory, Boulder, CO 80303 (1983).
  11. H. T. Mudd, C. H. Kruger, E. R. Murray, “Measurement of IR Laser Backscatter Spectra from Sulfuric Acid and Ammonium Sulfate Aerosols,” Appl. Opt. 21, 1146 (1982).
  12. D. Diermendjian, Electromagnetic Scattering on Spherical Polydispersions (American Elsevier, New York, 1969).
  13. D. Diermendjian, “Far-Infrared and Submillimetre Wave Attenuation by Clouds and Rain,” J. Appl. Meteorol. 14, 1584 (1975).
  14. F. Tampieri, C. Tomasi, “Size Distribution Models of Fog and Cloud Droplets in Terms of the Modified Gamma Function,” Tellus 28, 333 (1976).
  15. G. M. Hale, M. R. Querry, “Optical Constants of Water in the 200-nm to 200-μm Wavelength Region,” Appl. Opt. 12, 555 (1973).
  16. P. Chylek, “Extinction and Liquid Water Content of Fogs and Clouds,” J. Atmos. Sci. 35, 296 (1978).
  17. H. C. van de Hulst, Light Scattering by Small Particles (Wiley, New York, 1957).
  18. J. E. McDonald, “Large Sphere Limit of the Radar Back-scattering Coefficient,” Q. J. R. Meterol. Soc. 88, 183 (1962).
  19. R. G. Pinnick, H. J. Auvermann, “Response Characteristics of Knollenberg Light-Scattering Aerosol Counters,” J. Aerosol Sci. 10, 55 (1979).
  20. J. A. Garland, “Some Fog Droplet Size Distributions Obtained by an Impaction Method,” Q. J. R. Meteorol. Soc. 97, 483 (1971).
  21. R. G. Pinnick, S. G. Jennings, P. Chylek, H. J. Auvermann, “Verification of a Linear Relation Between IR Extinction, Absorption and Liquid Water Content of Fogs,” J. Atmos. Sci. 36, 1577 (1979).
  22. H. J. aufm Kampe, H. K. Weickmann, “Trabert’s Formula and the Determination of the Water Content in Clouds,” J. Meteorol. 9, 167 (1952).
  23. M. Diem, “Messung der grose con wolken-elementen,” Meteorol. Rundsch. 9, 261 (1948).
  24. H. K. Weickmann, H. J. aufm Kampe, “Physical Properties of Cumulus Clouds,” J. Meteorol. 10, 204 (1953).
  25. L. J. Battan, C. H. Reitan, Artificial Stimulation of Rain (Pergamon, New York, 1957), p. 184.

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