Abstract
We performed a series of aquaplanet simulations at the resolution from
50km to 6km with identical parameterization settings using the
Geophysical Fluid Dynamics Laboratory’s Atmosphere Model version 4
implemented with the two-moment Morrison-Gettelman cloud microphysics
with prognostic precipitation (GFDL AM4-MG2). At the finer resolution,
the global mean resolved-scale precipitation increases and that from
cumulus parameterization decreases. The model also simulates
less/thinner clouds over the low latitudes and more/thicker clouds over
the high latitudes as the resolution increases. The precipitation over
the deep tropics is investigated in detail. We find little resolution
sensitivity in the daily mean precipitation extremes. The increment of
the equatorial resolved precipitation with resolution mainly comes from
precipitation of moderate intensity occurring irrespective of changes in
vertical velocity intensity. We report a robust sensitivity in the
convective organization over the deep tropics to the model resolution.
In simulations of finer resolution, the localized convection is
suppressed, and the organized convective system associated with
large-scale circulations becomes more prominent.