The effect of ozone absorption is also seen in these figures. In the 305 nm case where ozone absorption is still relatively strong, there is little variation in surface irradiance with changing aerosol extinction for the two zenith angles due to the high ozone mass path. At 320 nm where ozone absorption is much weaker, the aerosol extinction mass path becomes more important as indicated by the variation in relative irradiance with solar zenith angle. Boundary Layer Ozone Sensitivity Ozone in the troposphere and particularly in the boundary layer play an important role in surface UV budgets. These ratios were assumed constant from the surface up to 1 km.
Typical surface mixing ratios vary considerably depending on meteorological conditions.
UV-B dose relative to dose calculated with a boundary layer ozone concentration of 10 ppb. This parameter must be treated with caution, however, as values can vary significantly depending on the wavelength interval and action spectrum used in calculating UV dose. This parameter also varies with respect to solar zenith angle and vertical ozone distribution. The effect of solar zenith angle in this case is similar to increasing the total column ozone depth as path length increases nonlinearly with increasing zenith angle, effectively increasing the ozone column depth needed to penetrate to the surface. On the Disproportionate Role of Tropospheric Ozone as a Filter Against Solar UV-B Radiation.