Radiation is treated in models using separate simulations, so-called radiation transport models. This takes place in the following steps; the procedure may be slightly modified in the specific implementation:
First, the densities of the components of the air are transmitted to the radiation model.
The radiation properties of the matter are then calculated using these densities and tabulated spectra of the substances.
Now the spectral radiance is calculated by solving the radiation transfer equation.
By spectrally integrating the convergence of the radiation flux density, thermal power densities are determined, which are transmitted back to the dynamic core. This shows heating rates.
Since solving the radiation transfer equation would lead to a global linear system of equations, the atmosphere is divided into non-interacting columns that have at least the horizontal extent of a grid cell.