Abstract
Single-column models (SCMs) are often used to evaluate model physics and
aid parameterization development. However, few studies have
systematically compared the results obtained using 1D setups with those
of their corresponding 3D models, and examined what factors potentially
impact their comparability. This paper addresses these questions. We
focus on the application of SCMs under idealized RCE conditions and use
a multi-column model (MCM) setup as stepping stone for a 3D model. We
find that convective organization in the MCM depends at least as much on
the convection scheme used as on other mechanisms known to organize
convection (e.g., radiative feedback). Moreover, convective organization
emerges as a robust factor affecting SCM-MCM comparability, with more
aggregated states in 3D associated with larger behavior deviations from
the 1D counterpart. This is found across five convection schemes and
applies to simulated mean states, linear responses to small tendency
perturbations, and adjustments to doubled-CO2 forcing. Applying a
“model-as-truth” approach, we find that even when convection is
organized, behavior differences between pairs of schemes in the SCM are
largely preserved in the MCM. This indicates that when model physics
produces accurate behavior in a 1D setup, it will be more likely to do
so in a 3D setup. We also demonstrate the practical value of linear
responses by showing that they can accurately predict an SCM’s
tropospheric adjustment to doubled-CO2 forcing.