On the resolution sensitivity of equatorial precipitation in a GFDL global atmospheric model

Publication Year
2023

Type

Journal Article
Abstract

We performed a series of aquaplanet simulations at the horizontal 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. Changes of the equatorial resolved precipitation with resolution cannot be fully explained by the resolution dependence in the vertical velocity amplitude. 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.

Journal
Journal of Advances in Modeling Earth Systems
Volume
15
Issue
10
Pages
e2022MS003300