Abstract

Two independent methods of measuring the transmittance of cirrus clouds are compared. Both used a CO2 pulsed Doppler lidar at a wavelength of 10.59 μm. The first method used backscatter from the calibration target El Chichon stratospheric cloud that was present over Boulder in 1982 and 1983. The second method used conical lidar scans at different zenith angles when uniform cirrus decks were present. Extinction coefficients measured from both methods average 0.1 km−1 for tenuous cirrus 1.0 km thick to 0.78 km−1 for cirrus several kilometers thick. There is a wide standard deviation in extinction values. Extinction-to-backscatter ratios S vary from <1000 sr for tenuous clouds to 2600 sr for dense clouds. Mie scattering and extinction calculations for spherical ice particles of 10–50 μm in radius lead to ratios S > 2000 sr, so long as the ice absorption is entered into the calculations. The backscattering ratio for ice cylinders is 1 order of magnitude lower than for spheres. Backscatter in the IR may, therefore, be reasonably well modeled by some combination of spheres and cylinders. Cloud thickness statistics from lidar returns show that cirrus decks average ~500 m thick. Clouds thinner than 300 m were often overlooked by the unaided surface-based observer. These preliminary results are in rather close agreement with the lowtran 6 cirrus cloud model predictions.

© 1988 Optical Society of America

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References

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  1. R. G. Stone, “A Compendium on Cirrus and Cirrus Forecasting,” Air Weather Service Technical Report AWS TR 105-130, USAF, Scott AFB, IL (1957).
  2. D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).
  3. W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
    [CrossRef]
  4. F. F. Hall, “The Effect of Cirrus Clouds on 8–13-μum Infrared Sky Radiance,” Appl. Opt. 7, 891 (1968).
    [CrossRef] [PubMed]
  5. S. K. Cox, “Observations of Cloud Infrared Effective Emissivity,” J. Atmos. Sci. 33, 287 (1976).
    [CrossRef]
  6. G. L. Stephens, P. J. Webster, “Clouds and Climate: Sensitivity of Simple Systems,” J. Atmos. Sci. 38, 235 (1981).
    [CrossRef]
  7. F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.
  8. L. S. Rothman et al., “AFGL Atmospheric Absorption Line Parameters Compilation: 1982 Edition,” Appl. Opt. 22, 2247 (1983).
    [CrossRef] [PubMed]
  9. M. J. Post, J. F. Morrow, D. B. Jensen, “beta: A Program for Calculating and Achieving Backscattering Profiles Taken with the NOAA Coherent Lidar System,” NOAA Tech. Memo. ERL WPL-113, Boulder, CO (1983).
  10. J. D. Klett, “Stable Analytical Inversion Solution for Processing Lidar Returns,” Appl. Opt. 20, 211 (1981).
    [CrossRef] [PubMed]
  11. C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
    [CrossRef]
  12. J. C. Johnson, Physical Meteorology (Wiley, New York, 1954).
  13. J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
    [CrossRef]
  14. B. M. Herman, M. A. Box, J. A. Reagan, C. M. Moore, “Alternate Approach to the Analysis of Solar Photometer Data,” Appl. Opt. 20, 2925 (1981).
    [CrossRef] [PubMed]
  15. E. L. Crow, F. A. Davis, M. W. Maxfield, Statistics Manual (Dover, New York, 1960).
  16. W. Carnuth, R. Reiter, “Cloud Extinction Profile Measurements by Lidar Using Klett’s Inversion Method,” Appl. Opt. 25, 2899 (1986).
    [CrossRef] [PubMed]
  17. I. D. Cohen, “Cirrus Particle Distribution Study, Part 8,” AFGL-TR-81-0316, Meteorology Division, Air Force Geophysics Laboratory, Hanscom AFB, MA (1981), 110 pp.
  18. A. Gross, M. J. Post, F. F. Hall, “Depolarization, Backscatter, and Attenuation of CO2 Lidar by Cirrus Clouds,” Appl. Opt. 23, 2518 (1984).
    [CrossRef] [PubMed]
  19. A. J. Heymsfield, NCAR, Boulder, CO; private communication (1987).
  20. C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
    [CrossRef]
  21. C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).
  22. S. G. Warren, “Optical Constants of Ice from the Ultraviolet to the Microwave,” Appl. Opt. 23, 1206 (1984).
    [CrossRef] [PubMed]
  23. J. V. Dave, “Scattering of Visible Light by Large Water Spheres,” Appl. Opt. 8, 155 (1969).
    [CrossRef] [PubMed]

1987

C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
[CrossRef]

1986

1984

1983

1981

1980

J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
[CrossRef]

1978

C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
[CrossRef]

1976

S. K. Cox, “Observations of Cloud Infrared Effective Emissivity,” J. Atmos. Sci. 33, 287 (1976).
[CrossRef]

1969

1968

1965

W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
[CrossRef]

1961

D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).

Abshire, N. L.

C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
[CrossRef]

Bohren, C. F.

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

Box, M. A.

Carnuth, W.

Cohen, I. D.

I. D. Cohen, “Cirrus Particle Distribution Study, Part 8,” AFGL-TR-81-0316, Meteorology Division, Air Force Geophysics Laboratory, Hanscom AFB, MA (1981), 110 pp.

Cox, S. K.

S. K. Cox, “Observations of Cloud Infrared Effective Emissivity,” J. Atmos. Sci. 33, 287 (1976).
[CrossRef]

Crow, E. L.

E. L. Crow, F. A. Davis, M. W. Maxfield, Statistics Manual (Dover, New York, 1960).

Dave, J. V.

Davis, F. A.

E. L. Crow, F. A. Davis, M. W. Maxfield, Statistics Manual (Dover, New York, 1960).

Derr, V. E.

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

Dilley, A. C.

C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
[CrossRef]

Gross, A.

Hales, J. V.

W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
[CrossRef]

Hall, F. F.

A. Gross, M. J. Post, F. F. Hall, “Depolarization, Backscatter, and Attenuation of CO2 Lidar by Cirrus Clouds,” Appl. Opt. 23, 2518 (1984).
[CrossRef] [PubMed]

F. F. Hall, “The Effect of Cirrus Clouds on 8–13-μum Infrared Sky Radiance,” Appl. Opt. 7, 891 (1968).
[CrossRef] [PubMed]

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

Henderson, D.

W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
[CrossRef]

Herman, B. M.

B. M. Herman, M. A. Box, J. A. Reagan, C. M. Moore, “Alternate Approach to the Analysis of Solar Photometer Data,” Appl. Opt. 20, 2925 (1981).
[CrossRef] [PubMed]

J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
[CrossRef]

Heymsfield, A. J.

A. J. Heymsfield, NCAR, Boulder, CO; private communication (1987).

Huffman, D. R.

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

Jensen, D. B.

M. J. Post, J. F. Morrow, D. B. Jensen, “beta: A Program for Calculating and Achieving Backscattering Profiles Taken with the NOAA Coherent Lidar System,” NOAA Tech. Memo. ERL WPL-113, Boulder, CO (1983).

Johnson, J. C.

J. C. Johnson, Physical Meteorology (Wiley, New York, 1954).

Klett, J. D.

Lerfald, G. M.

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

Lienesch, J. H.

D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).

Maxfield, M. W.

E. L. Crow, F. A. Davis, M. W. Maxfield, Statistics Manual (Dover, New York, 1960).

McNice, G. T.

C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
[CrossRef]

Moore, C. M.

Morrow, J. F.

M. J. Post, J. F. Morrow, D. B. Jensen, “beta: A Program for Calculating and Achieving Backscattering Profiles Taken with the NOAA Coherent Lidar System,” NOAA Tech. Memo. ERL WPL-113, Boulder, CO (1983).

Platt, C. M. R.

C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
[CrossRef]

C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
[CrossRef]

Post, M. J.

A. Gross, M. J. Post, F. F. Hall, “Depolarization, Backscatter, and Attenuation of CO2 Lidar by Cirrus Clouds,” Appl. Opt. 23, 2518 (1984).
[CrossRef] [PubMed]

M. J. Post, J. F. Morrow, D. B. Jensen, “beta: A Program for Calculating and Achieving Backscattering Profiles Taken with the NOAA Coherent Lidar System,” NOAA Tech. Memo. ERL WPL-113, Boulder, CO (1983).

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

Reagan, J. A.

B. M. Herman, M. A. Box, J. A. Reagan, C. M. Moore, “Alternate Approach to the Analysis of Solar Photometer Data,” Appl. Opt. 20, 2925 (1981).
[CrossRef] [PubMed]

J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
[CrossRef]

Reiter, R.

Richter, R. A.

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

Rothman, L. S.

Scott, J. C.

C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
[CrossRef]

Spinhirne, J. D.

J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
[CrossRef]

Stephens, G. L.

G. L. Stephens, P. J. Webster, “Clouds and Climate: Sensitivity of Simple Systems,” J. Atmos. Sci. 38, 235 (1981).
[CrossRef]

Stone, R. G.

R. G. Stone, “A Compendium on Cirrus and Cirrus Forecasting,” Air Weather Service Technical Report AWS TR 105-130, USAF, Scott AFB, IL (1957).

Wark, D. W.

D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).

Warren, S. G.

Webster, P. J.

G. L. Stephens, P. J. Webster, “Clouds and Climate: Sensitivity of Simple Systems,” J. Atmos. Sci. 38, 235 (1981).
[CrossRef]

Yamamoto, G.

D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).

Zdunkowski, W. D.

W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
[CrossRef]

Appl. Opt.

J. Appl. Meteorol.

J. D. Spinhirne, J. A. Reagan, B. M. Herman, “Vertical Distribution of Aerosol Extinction Cross Section and Inference of Aerosol Imaginary Index in the Troposphere by Lidar Technique,” J. Appl. Meteorol. 19, 426 (1980).
[CrossRef]

C. M. R. Platt, N. L. Abshire, G. T. McNice, “Some Micro-physical Properties of an Ice Cloud from Lidar Observation of Horizontally’ Oriented Crystals,” J. Appl. Meteorol. 17, 1220 (1978).
[CrossRef]

J. Atmos. Sci.

C. M. R. Platt, J. C. Scott, A. C. Dilley, “Remote Sounding of High Clouds. Part VI: Optical Properties of Midlatitude and Tropical Cirrus,” J. Atmos. Sci. 44, 729 (1987).
[CrossRef]

D. W. Wark, G. Yamamoto, J. H. Lienesch, “Methods of Estimating Infrared Flux and Surface Temperatures from Meteorological Satellites,” J. Atmos. Sci. 18, 369 (1961).

S. K. Cox, “Observations of Cloud Infrared Effective Emissivity,” J. Atmos. Sci. 33, 287 (1976).
[CrossRef]

G. L. Stephens, P. J. Webster, “Clouds and Climate: Sensitivity of Simple Systems,” J. Atmos. Sci. 38, 235 (1981).
[CrossRef]

Tellus

W. D. Zdunkowski, D. Henderson, J. V. Hales, “The Influence of Haze on Infrared Measurements Detected by Space Vehicles,” Tellus 17, 147 (1965).
[CrossRef]

Other

F. F. Hall, M. J. Post, R. A. Richter, G. M. Lerfald, V. E. Derr, “Cirrus Cloud Model,” in Atmospheric Transmittance/Radiance: Computer Code lowtran 6, F. X. Kneizys et al., Eds., AFGL-TR-83-0187, Air Force Geophysics Laboratory, Hanscom AFB, MA (1983), pp. 58–67.

M. J. Post, J. F. Morrow, D. B. Jensen, “beta: A Program for Calculating and Achieving Backscattering Profiles Taken with the NOAA Coherent Lidar System,” NOAA Tech. Memo. ERL WPL-113, Boulder, CO (1983).

E. L. Crow, F. A. Davis, M. W. Maxfield, Statistics Manual (Dover, New York, 1960).

A. J. Heymsfield, NCAR, Boulder, CO; private communication (1987).

C. F. Bohren, D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley, New York, 1983).

I. D. Cohen, “Cirrus Particle Distribution Study, Part 8,” AFGL-TR-81-0316, Meteorology Division, Air Force Geophysics Laboratory, Hanscom AFB, MA (1981), 110 pp.

J. C. Johnson, Physical Meteorology (Wiley, New York, 1954).

R. G. Stone, “A Compendium on Cirrus and Cirrus Forecasting,” Air Weather Service Technical Report AWS TR 105-130, USAF, Scott AFB, IL (1957).

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Figures (7)

Fig. 1
Fig. 1

Scattergram of over 120 cirrus cloud 10.6-μm backscatter measurements, uncorrected for extinction within the cirrus. The sloping line is the least-squares best fit. Backscatter coefficient units are m−1 sr−1. Day-to-day absolute calibration uncertainties are ~10%.

Fig. 2
Fig. 2

10.6-μm backscatter uncorrected for cirrus extinction vs height for a thick cirrus layer between 6.5 and 11.6 km. The lower-altitude return is from aerosols. Although absolute uncertainties in calibration are ~10% (about the radius of the data circles), the relative uncertainties from one range gate to the next are <1%.

Fig. 3
Fig. 3

10.6-μm backscatter uncorrected for cirrus extinction versus height for a thick cirrus layer between 6.2 and 8.3 km and two higher thinner layers. Lidar pulse energy was 0.95 J, and 1000 pulses were averaged.

Fig. 4
Fig. 4

Lidar integrated backscattered radiance (in arbitrary units) vs time as a cirrus deck of varying thickness advected through the vertical beam. A decreased signal signifies a thinner cirrus cloud. This diagram illustrates the difficulty in assigning absolute error bars to the reduced data; although a 20-s run with 200 lidar pulses produces a 10% probable error for a constant scatterer, the cloud can show real changes in a 20-s interval.

Fig. 5
Fig. 5

Cirrus attenuation of El Chichon backscatter for integrated cirrus beta values, b t β l d l ,from base b to top t of cirrus layer. Estimated error bars are consistent with the data circles as before.

Fig. 6
Fig. 6

Langley plot for determining cirrus extinction layer by layer from the base of the cloud. The slopes of the lines become more negative for increasing depths into the cloud, indicating higher scattering ratios. The backscatter values are also greater with increasing distance into the cloud, where the ice loading and particle concentrations are greater. Different symbols are used to help identify each range-resolved height gate within the cloud: ●, 1.5 km; ×, 2.3 km; etc.

Fig. 7
Fig. 7

Langley plot as in Fig. 6 but for a complex multiple-layer cirrus. The more gradually sloping line for 2.1 km above the cloud base was in a low-particle density region between the two principal cirrus decks, where aircraft collection showed a number of small (10-μm radius) round ice crystals.

Tables (2)

Tables Icon

Table I Summary of Langley Plot-Derived Cirrus IR Optical Properties; Probable Errors for β, S. and σ are ~10%

Tables Icon

Table II Cirrus Beta Statistics, 31 Oct. 1986 FIRE Data (β Units are ×E-8 1/m 1/sr)

Equations (5)

Equations on this page are rendered with MathJax. Learn more.

β EC = β ^ EC exp [ - 2 b t σ ( l ) d l ] = β ^ EC exp ( - 2 l i = 1 n σ i )
β ^ EC ( 1 - 2 l i = 1 n σ i ) ,
S = σ / β ,
σ = 0.14 L km - 1 ( L is cloud thickness in km )
b t β l d l ,

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