This page evaluates the RRTMGP gas optics scheme, designed for weather and climate applications. The comparisons below use the 50 profiles of the "Evaluation-1" CKDMIP dataset. The reference calculations were performed using LBLRTM to generate the high resolution absorption spectra and the CKDMIP software to perform the radiative transfer. See also the results for the earlier RRTMG gas optics scheme, and also those from a Neural Network approximation to RRTMGP.
Longwave
The longwave gas optics scheme uses a total of 256 g-points (k terms) in 16 bands. The evaluation has been performed using radiative transfer with four zenith angles in each hemisphere (8-stream). The following plots evaluate fluxes and heating rates for the four CKDMIP greenhouse-gas scenarios "Present", "Preindustrial", "Glacial Maximum" and "Future". The comparison shares some of the features of the ecRad-RRTMG results, but are generally improved with less wiggles in the heating rate errors.
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