Radiative transfer in the region with solar and infrared spectra overlap

Three schemes dealing with the radiative transfer in the region where the solar and infrared spectra overlap are discussed and compared, among which two schemes are commonly used in current climate models, and the other is a newly proposed one. In single-column simulations for multi-layers atmosphere, the scheme, which deposits the solar energy in the infrared spectrum into the shortwave bands, can produce errors over 8 W m−2 in fluxes at the surface under the clear sky condition and at the cloud top in the cloudy sky due to ignoring the strong atmosphere absorption in the infrared spectrum. Another scheme that used in RRTMG model can produce over 3 W m−2 errors in high cloud case because of the large bias of optical properties in the additional independent band. The errors of the new scheme are less than 2 W m−2 in fluxes and smaller in heating rate for both the clear sky and cloudy sky. The band-by-band results of heating rate, downward flux at the surface and upward flux at the top of the atmosphere are also shown. The newly proposed scheme produces higher accuracy than others two schemes, especially in the infrared spectrum of 4-7.14 µm.