Mathematical Sciences, UW - Milwaukee
Do cloud parameterizations have to be so kludgy?
Room 811 AOSS, April 3, 2017, 3:30 PM
Climate projections are now consulted by policymakers, and hence climate models ought to be made as reliable as feasible. Unfortunately,
uncertainties are introduced by kludgy assumptions in the climate models’ cloud parameterizations. For instance, different microphysics schemes are often used for stratiform and convective clouds, and the convective microphysics is often crude. These assumptions are often excused with a shrug and a comment that “it’s only a parameterization.” Does it need to be this way?
This talk will present an alternative parameterization methodology that is based more closely on the governing equations of fluid flow. In particular, it uses higher-order closure to treat all cloud types, including stratiform, shallow cumulus, and deep cumulus. This unification allows, in turn, the same microphysics scheme to be used in all cloud types. Results from a global climate simulation will be presented.