Cloud fraction

Cloud fraction is the percentage of each pixel in satellite imagery or each grid box in a weather or climate model that is covered with clouds. A cloud fraction of one means the pixel is completely covered with clouds, while a cloud fraction of zero represents a totally cloud free pixel.¹ Cloud fraction is important for the modeling of downward radiation.² Unlike sky cover, cloud fraction is often treated as the proportion of a horizontal area covered by clouds as viewed from below.³

References

Cloud Fraction NASA Earth Observatory, January 2005.
L. Chen, G. Yan, T. Wang, H. Ren, J. Calbó, J. Zhao, R. McKenzie (2012), Estimation of surface shortwave radiation components under all sky conditions: Modeling and sensitivity analysis, Remote Sensing of Environment, 123: 457–469.
Kassianov, Evgueni; Long, Charles N.; Ovtchinnikov, Mikhail (1 January 2005). "Cloud Sky Cover versus Cloud Fraction: Whole-Sky Simulations and Observations". Journal of Applied Meteorology. 44 (1): 86–98. doi:10.1175/JAM-2184.1.

[1] Cloud Fraction NASA Earth Observatory, January 2005.

[2] L. Chen, G. Yan, T. Wang, H. Ren, J. Calbó, J. Zhao, R. McKenzie (2012), Estimation of surface shortwave radiation components under all sky conditions: Modeling and sensitivity analysis, Remote Sensing of Environment, 123: 457–469.

[3] Kassianov, Evgueni; Long, Charles N.; Ovtchinnikov, Mikhail (1 January 2005). "Cloud Sky Cover versus Cloud Fraction: Whole-Sky Simulations and Observations". Journal of Applied Meteorology. 44 (1): 86–98. doi:10.1175/JAM-2184.1.

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