Optimized Alternate Mapping Correlated K‐Distribution Method for Atmospheric Longwave Radiative Transfer

Abstract Radiative transfer models are widely applied in climate to simulate vertical temperature perturbations caused by external radiative forcings. A large part of is the infrared gaseous spectral transmittance scheme, which quantifies longwave atmospheric absorption. rapid called Optimized alternate Mapping Correlated K‐Distribution model (OMCKD), introduced this paper. To improve accuracy our scheme without increasing pseudo‐monochromatic calculations, we introduce optimal iteration method automatically tune equivalent absorption coefficients cumulative probability subspace. In addition, a new expression weighted black‐body radiation calculate coefficient. The OMCKD simulates heating rate and flux with errors less than 0.12 K d −1 0.35 W m −2 , respectively, below stratopause for standard profiles. also evaluated compared general circulation (RRTMG) realistic We found that can accurately produce rates generally captures forcings associated concentrations main greenhouse gases. Furthermore, number calculations 11.4% RRTMG, indicates computational cost.