Spectral Measurements of Solar Irradiance and Radiance in Clear and Cloudy Atmospheres - Short-Wave Solar Radiation in the Earth's Atmosphere - page 99

Fig. 3.11. Minimal value of the standard deviation over all data set of the airborne sounding.
Upper curve - upwelling irradiance, lower curve - downwelling irradiance
Fig. 3.12. Vertical profiles of the spectral albedo of the system “atmosphere plus surface”