A Satellite-Based Sky Luminance Model for the Tropics

Figure 7

An example of the curves 𝜑(𝑍)/𝜑(0) versus 𝑍 for cloud index 0.1<𝑛≤0.2 and different values of solar zenith angles 𝑍_𝑠. 𝑍 is the zenith angle of the sky subzone.