Resolution Sensitivity in Climate Models
The impact of changing the vertical velocity field with native grid resolution cannot be ignored in any effort to recover convergent solutions in AGCMs (these results reproduce resolution sensitivity in other AGCMs).
Vertical velocities follow〖∆x〗^(-1) scaling across typical GCM resolutions. Larger vertical velocities generate greater condensational/stratiform heating, while also causing greater subsidence drying. Both processes increase atmospheric stability with resolution, reducing the activity of parametrized convection.
Convergence experiments in ∆X ∆x (grid spacing) from 2˚ to 1/4˚ are completed with the CAM6 aqua-planets experiment configuration. Uncertainty remains on how to handle physics time-steps across resolutions, this work opted to scale in proportion to grid spacing.