In this case we include the US standard atmosphere, the corresponding Rayleigh scattering optical thickness and molecular absorption profiles are provided at 450 nm. In addition two aerosol layers are added: desert dust in the troposphere and sulfate in the stratosphere.

Setup:

• model atmosphere US-standard, scattering optical thickness provided in file tau_rayleigh_450nm_usstd.dat, molecular absorption optical thicknes in tau_absorption_450nm_usstd.dat. The file includes 2 columns where the first is the altitude of the layer boundaries in km, and the second is the layer optical thickness (e.g. the value for 0 km corresponds to the optical thickness for the layer from 0 to 1 km).
• desert dust aerosol between 0 and 3 km altitude with an optical thickness of 0.5. The aerosol optical properties are given in the file desert.cdf. The format of the file is the same as in case D4.
• sulfate aerosol between 20 and 21 km altitude with an optical thickness of 0.05 with optical properties from sulfate.cdf.
• wavelength: 450 nm
• Rayleigh depolarization factor: 0.03
• surface albedo: 0
• Earth radius: 6371 km

• Sun-observer geometries as defined in general settings:
  • viewing zenith angles (deg): [0, 9, 18, 26, 34, 41, 48, 54, 60, 65, 70, 74, 78, 81, 84, 86, 88, 89, 90] (up-looking at bottom of atmosphere, down-looking at top of atmosphere]
  • viewing azimuth angles (deg): 0-180, 10° increment
  • solar zenith angles (deg): [30, 60, 80, 87, 90, 93, 96, 99]
  • solar azimuth angle (deg): 0
  • sensor altitude (km): 0, 120