“…2.8 rapidly degrades. The approach initially followed in CMAM was to employ a more accurate IR scheme (Fomichev et al, 1993;Fomichev and Blanchet, 1995) in the stratosphere and mesosphere with a region of transition between the two schemes occurring over the range 40-7 hPa. More recently, additional improvements to the radiation above this transition region include a new 15 µm CO 2 parameterization (Fomichev et al, 1998), near-infrared CO 2 solar heating with non-LTE effects included (Ogibalov and Fomichev, 2003;, water vapor IR cooling, non-unit efficiency for solar O 3 heating in the mesosphere, solar O 2 heating in the Schumann-Runge bands and continuum, the effect of sphericity, and chemical heating (in the CCM-MAM version).…”