[GTP] GTP Seminar--Tiffany Shaw--March 4

[Silvia Gentile]

Joint GTP MMM Seminar


Physical Consistency in Subgrid-scale Parameterization for Climate Models
Tiffany Shaw
Center for Atmosphere Ocean Science, Courant Institute of Mathematical 
Sciences



It is well known that the transfers of energy and momentum by subgrid- 
scale processes such as convection, the breaking of small-scale internal 
gravity waves and boundary layer turbulence are important for the energy 
and momentum budgets of the resolved scales in a climate model. While 
energy and momentum conservation is important in general, little 
attention has been paid to the implications of these constraints in the 
parameterization of subgrid-scale processes. In this talk we will 
examine the importance of physical consistency in subgrid-scale 
parameterization for climate models. We will present a framework for 
subgrid-scale parameterization that respects energy and momentum 
conservation as well as the second law of thermodynamics, which is 
derived using Hamiltonian geophysical fluid dynamics and multiple scale 
asymptotics. The framework provides a concise understanding of the 
interactions between the resolved and subgrid scale energy and momentum 
by appealing to wave activity conservation laws. It also provides new 
measures to quantify and test the consistency of energy and momentum 
conservation in current subgrid-scale parameterizations. We will present 
the results of climate model simulations which clearly demonstrate that 
nonconservation in the parameterization of momentum transfers by 
small-scale internal gravity waves leads to non-negligible errors which 
occur throughout the depth of the atmosphere.


March 4, 2010
Room 1022
Lecture 3:30pm
Foothills Laboratory 2
3450 Mitchell Lane
Boulder Colorado
  303-497-8700