BCC_AGCM2.0 originates from the community atmospheric model version 3 (CAM3) developed by the National Center for Atmospheric Research(NCAR). The dynamics in BCC_AGCM2.0 is substantially different from the Eulerian spectral formulation of the dynamical equations in CAM3. The dynamical core of BCC_AGCM2.0 is reference atmosphere described in Wu et al.(2008), which demonstrated that the use of a reference atmosphere can substantially improve the calculation of pressure gradient force and thus model performance at regional and global scales, especially for the tropospheric temperature and winds. Several new physical parameterizations (Wu,2010) have been applied to replace the corresponding original ones.
 

The major modifications of the model physics in BCC_AGCM2.0 include
(1) A new convection scheme, which is generated from the Zhang and McFarlane’s scheme but modified (Zhang and Mu, 2005),
(2) A dry adiabatic adjustment scheme (Yan H. 1987) in which potential temperature is conserved,
(3) A modified scheme to calculate the sensible heat and moisture fluxes over the open ocean which takes into account the effect of ocean waves on the latent and sensible heat fluxes,
(4) An empirical equation to compute the snow cover fraction (Wu T. and Wu G. 2004).
The model equations are formulated in a horizontal T42 spectral resolution (approximately 2.8°latitude ×2.8°longitude grid) and a terrain-following hybrid vertical coordinate with 26 levels and a rigid lid at 2.914mb.