The model parameters follow the ‘Real Skies’ ideas described in “The Greenhouse Effect” page.
In addition to some parameters required for correcting inhomogeneous temperature profiles, most of the parameters relate to Greenhouse gases: water, carbon dioxide, methane, Tropospheric ozone and nitrous oxide. The global population was included representing minor other Greenhouse gases although the empirical parameters determined by variance minimisation estimates these contributions to be nearly negligible.
For each Greenhouse gas several parameters were included those relating to:
• Effective Density. See note 8 of ‘The Greenhouse Effect’ page, effective density is a combination of two factors in Schwarzschild’s Radiative Transfer Equation: number density and the absorption cross-section. Thes may be combined for all gases for any particular frequency by summing the number density times the absorption cross-section.
• Effective Emission Altitude. See note 11 of ‘The Greenhouse Effect’ page. Two empirical parameters are included in the model for each gas: (i) the saturation zone and (ii) the broadening and overlap zone.
Empirical parameters are included for humidity and cloud cover effects for long-term, seasonal and shorter-term.
The total contributions from water and from carbon dioxide were constrained to lie in the ranges of 65%-76% and 17%-25%, respectively, consistent with the range of estimates by other researchers. Although the process of minimising variance never approached these constraints.