Coupled Physical Model, CM3 GFDL's successful model, CM2.1
(Delworth et al., 2006), was used as the starting point to
develop the next-generation CM3 coupled model. The major
development effort for CM3 focused on the atmosphere component.
The update from the CM2.1 atmospheric component (AM2; GFDL
GAMDT, 2004) to the new AM3 component in CM3 (Donner et al.,
2011) was intended to allow us to address important questions -
What are the roles of aerosol-cloud interactions, specifically
indirect effects of aerosols? - What are the dominant chemistry-
climate interactions? - What is the role of coupling to the
stratosphere (and stratospheric chemistry)? In particular, AM3
includes new treatments of deep and shallow cumulus convection,
cloud droplet activation by aerosols (i.e., aerosol indirect
effect), subgrid variability of stratiform vertical velocities
for droplet activation, and atmospheric chemistry and aerosols
driven by emissions with advective, convective, and turbulent
transport. AM3 employs a cubed-sphere