Abstract

Quantitative data are presented to illustrate the infrared spectral radiance of the sky under a variety of situations. A qualitative discussion of the dominant spectral features is given to show the importance of the emission and scattering processes, the effect of angle of elevation, angle of azimuth, sun angle, and cloud cover.

© 1960 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. A. Oetjen, E. E. Bell, J. Young, and L. Eisner, J. Opt. Soc. Am. 50, 1308 (1960).
    [Crossref]
  2. F. Möller, Handbuch der Physik, edited by E. Flügge (Springer-Verlag, Berlin, Vienna, 1957), Vol. 48.
  3. M. Migeotte, L. Neven, and J. Swenson, Mém. soc. roy. sci. Liége, Special Vol. Nos.  1 and 2 (1956–57).
  4. J. H. Taylor and H. W. Yates, J. Opt. Soc. Am. 47, 223 (1957).
    [Crossref]
  5. J. H. Shaw, D. E. Burch, R. W. Sloan, and Dudley Williams, Mém. soc. roy. sci. Liége, Quatrieme Ser. 18, 43 (1957).
  6. D. E. Burch and J. H. Shaw, J. Opt. Soc. Am. 47, 227 (1957).
    [Crossref]
  7. R. Sloan, J. H. Shaw, and Dudley Williams, J. Opt. Soc. Am. 45, 455 (1955).
    [Crossref]
  8. R. Sloan, J. H. Shaw, and Dudley Williams, J. Opt. Soc. Am. 46, 543 (1956).
    [Crossref]
  9. R. M. Goody, Quart. J. Roy. Meteorol. Soc. 83, 517 (1957).
    [Crossref]
  10. R. M. Goody, Quart. J. Roy. Meteorol. Soc. 78, 165 (1952).
    [Crossref]
  11. J. N. Howard, D. E. Burch, and Dudley Williams, J. Opt. Soc. Am. 46, 334 (1956).
    [Crossref]

1960 (1)

1957 (4)

J. H. Taylor and H. W. Yates, J. Opt. Soc. Am. 47, 223 (1957).
[Crossref]

J. H. Shaw, D. E. Burch, R. W. Sloan, and Dudley Williams, Mém. soc. roy. sci. Liége, Quatrieme Ser. 18, 43 (1957).

D. E. Burch and J. H. Shaw, J. Opt. Soc. Am. 47, 227 (1957).
[Crossref]

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 83, 517 (1957).
[Crossref]

1956 (2)

1955 (1)

1952 (1)

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 78, 165 (1952).
[Crossref]

Bell, E. E.

Burch, D. E.

J. H. Shaw, D. E. Burch, R. W. Sloan, and Dudley Williams, Mém. soc. roy. sci. Liége, Quatrieme Ser. 18, 43 (1957).

D. E. Burch and J. H. Shaw, J. Opt. Soc. Am. 47, 227 (1957).
[Crossref]

J. N. Howard, D. E. Burch, and Dudley Williams, J. Opt. Soc. Am. 46, 334 (1956).
[Crossref]

Eisner, L.

Goody, R. M.

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 83, 517 (1957).
[Crossref]

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 78, 165 (1952).
[Crossref]

Howard, J. N.

Migeotte, M.

M. Migeotte, L. Neven, and J. Swenson, Mém. soc. roy. sci. Liége, Special Vol. Nos.  1 and 2 (1956–57).

Möller, F.

F. Möller, Handbuch der Physik, edited by E. Flügge (Springer-Verlag, Berlin, Vienna, 1957), Vol. 48.

Neven, L.

M. Migeotte, L. Neven, and J. Swenson, Mém. soc. roy. sci. Liége, Special Vol. Nos.  1 and 2 (1956–57).

Oetjen, R. A.

Shaw, J. H.

Sloan, R.

Sloan, R. W.

J. H. Shaw, D. E. Burch, R. W. Sloan, and Dudley Williams, Mém. soc. roy. sci. Liége, Quatrieme Ser. 18, 43 (1957).

Swenson, J.

M. Migeotte, L. Neven, and J. Swenson, Mém. soc. roy. sci. Liége, Special Vol. Nos.  1 and 2 (1956–57).

Taylor, J. H.

Williams, Dudley

Yates, H. W.

Young, J.

J. Opt. Soc. Am. (6)

Mém. soc. roy. sci. Liége (1)

M. Migeotte, L. Neven, and J. Swenson, Mém. soc. roy. sci. Liége, Special Vol. Nos.  1 and 2 (1956–57).

Mém. soc. roy. sci. Liége, Quatrieme Ser. (1)

J. H. Shaw, D. E. Burch, R. W. Sloan, and Dudley Williams, Mém. soc. roy. sci. Liége, Quatrieme Ser. 18, 43 (1957).

Quart. J. Roy. Meteorol. Soc. (2)

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 83, 517 (1957).
[Crossref]

R. M. Goody, Quart. J. Roy. Meteorol. Soc. 78, 165 (1952).
[Crossref]

Other (1)

F. Möller, Handbuch der Physik, edited by E. Flügge (Springer-Verlag, Berlin, Vienna, 1957), Vol. 48.

Cited By

OSA participates in Crossref's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (11)

Fig. 1
Fig. 1

An idealized spectral radiance of the sun, emitting atmosphere, sunlit cloud, and sunlight-scattering clear sky.

Fig. 2
Fig. 2

Spectral radiance of a blackbody with temperatures in the range of the ambient air temperature.

Fig. 3
Fig. 3

The spectral radiance of a clear sky for several angles of elevation above the horizon. These spectra were measured in September, at night, from the Elk Park station, Colorado, 11 000 feet above sea level, when the ambient temperature was 8°C. The elevation angles in the sequence are 0°, 1.8°, 3.6°, 7.2°, 14.5°, 30°, and 90°.

Fig. 4
Fig. 4

The spectral radiance of a clear sky for several angles of elevation above the horizon. These spectra were measured in June, from Cocoa Beach, Florida, when the ambient temperature was about 27°C. The elevation angles in the sequence are 0°, 1.8°, 3.6°, 7.2°, 14.5°, 30°, and 90°. The extra dashed curve is explained in the text.

Fig. 5
Fig. 5

Zenith sky spectral radiance showing the large variation with ambient temperature. The dashed curves are the spectral radiances of blackbodies at the ambient temperatures corresponding to the times when the separate measurements were made. The low-temperature measurement was made from the summit of Pikes Peak, Colorado, 14 110 feet above sea level, and the high-temperature measurement was made from Colorado Spring, Colorado, 6000 feet above sea level.

Fig. 6
Fig. 6

Comparison of theoretical and experimental variation of emissivity with elevation angle. The experimental points are plotted as dots for the 0° to 90° elevation range and as crosses for the 90° to 180° range. The data were obtained at Sacramento Peak, New Mexico, 9200 ft above sea level, in August, at a wavelength of 4.62 μ.

Fig. 7
Fig. 7

The spectral radiance of the under side of a dark cumulus cloud. The dashed radiance curves are blackbody curves for the ambient air temperature and for the indicated cloud temperature. The measurement was made from the summit of Pikes Peak at an elevation angle of 14.5° in an otherwise clear sky.

Fig. 8
Fig. 8

The spectral radiance of sky covered with cirrus clouds at several angles of elevation. The spectra were measured in June, from Cocoa Beach, Florida, when the temperature was about 28°C. The elevation angles are 0°, 1.8°, 3.6°, 7.2°, 14.5°, 30°, and 90°.

Fig. 9
Fig. 9

The spectral radiance of a clear sky, showing the elevation angle dependence of the scattered radiation. The measurements were made from Colorado Springs, Colorado, near noon in September. The elevation angles are 0° (highest curve), 7.2° and 30° (lowest curve). Note that the radiance values for the shortwave portion are 10 times larger than the ordinate scale shown.

Fig. 10
Fig. 10

Spectral radiance of a clear zenith sky at Cocoa Beach, Florida, showing the effect of the position of the sun on the amount of radiation scattered from the zenith sky. Note the ordinate scale change for the short-wave portion of the dashed curve. Curve A, sun elevation 77°, temperature 30°C; Curve B, sun elevation 41°, temperature 25.5°C; Curve C, sun elevation 15°, temperature 26.5°C.

Fig. 11
Fig. 11

The spectral radiance of a clear sky at Cocoa Beach, Florida, showing the elevation angle dependence of the scattered radiation at 1.13-μ wavelength.