Short-term variability of overcast brightness

Applied Optics

Volumn 44, Issue 27, 2005, Pages 5704-5711

  Lee Jr , Raymond L ^a   Hernández Andrés, Javier ^b  

^a UNITED STATES NAVAL ACADEMY   (United States)

^b UNIVERSITY OF GRANADA   (Spain)

Author keywords

[No Author keywords available]

Indexed keywords

CLOUDS; FOG; IMAGE PROCESSING; LUMINESCENCE; SNOW; SUN; TIME SERIES ANALYSIS;

OPTICAL DEPTH; OVERCAST BRIGHTNESS; TEMPORAL VARIABILITY; VISIBLE-WAVELENGTH SPECTRA;

ATMOSPHERIC SPECTRA;

EID: 27144518513     PISSN: 1559128X     EISSN: 15394522     Source Type: Journal    
DOI: 10.1364/AO.44.005704     Document Type: Conference Paper

References (18)

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10. See Ref. 1, Sect. 2 for details of our overcast definition. Here we use "brightness" as a shorthand for the photometric measures of illuminance and luminance, while recognizing that brightness has several psychophysical definitions, including those that relate it quantitatively to luminance. For details, see G. Wyszecki and W. S. Stiles, Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd ed. (Wiley, New York, 1982), pp. 493-494.
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13. 6 are lux, and its curvilinear correlation coefficient is 0.9734 for the 10-17-03 time series.
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15. el differ and thus so do the maximum periods (and minimum frequencies) graphed in Fig. 4.
16. v is both extensive and long-lived. An important early study is S. Fritz, "Illuminance and luminance under overcast skies," J. Opt. Soc. Am. 45, 820-825 (1955).
17. We distinguish between fog and a higher-altitude overcast only when the two cloud types' movement and structure clearly differ. For our ground-based observations, this distinction requires that the fog occasionally thins enough to let us see the overcast above it. For the canonical definition of fog, see T. S. Glickman, ed., Glossary of Meteorology, 2nd ed. (American Meteorological Society, Boston, 2000), pp. 304-305.
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