Speaker: Max Gunzburger, Florida State University
Title: A multi-resolution method for climate system modeling: Application of Spherical Centroidal Voronoi tessellations
Abstract:
During the next decade and beyond, climate system models
will be challenged to resolve scales and processes that are far
beyond their current scope. Each climate system component has its
prototypical example of an unresolved process that may strongly
influence the global climate system, ranging from eddy activity
within ocean models, to ice streams within ice sheet models, to
surface hydrological processes within land system models, to cloud
processes within atmosphere models. These new demands will almost
certainly result in the develop of multi-resolution schemes that are
able, at least regional, to faithfully simulate these fine-scale
processes. Spherical Centroidal Voronoi Tessellations (SCVTs) offer
one potential path toward the development of robust, multi-resolution
climate system component models. SCVTs allow for the generation of
high quality Voronoi diagrams and Delaunay triangulations through the
use of an intuitive, user-defined density function. In each of the
examples provided, this method results in high-quality meshes where
the quality measures are guaranteed to improve as the number of nodes
is increased. Real-world examples are developed for the Greenland ice
sheet and the North Atlantic ocean. Idealized examples are developed
for ocean-ice shelf interaction and for regional atmospheric
modeling. In addition to defining, developing and exhibiting SCVTs,
we pair this mesh generation technique with a previously developed
finite-volume method. Our numerical example is based on the nonlinear
shallow-water equations spanning the entire surface of the sphere.
This example is used to elucidate both the potential benefits of this
multi-resolution method and the challenges ahead. (This is joint work
with Lili Ju of the University of South Carolina and Todd Ringler of
the Los Alamos National Laboratory.)
Place: Science and Technology Building I, Room 242
Refreshments will be served before the talk at 3:00 p.m. in Room 222.
Department of Mathematical Sciences
George Mason University
4400 University Drive, MS 3F2
Fairfax, VA 22030-4444
http://math.gmu.edu/
Tel. 703-993-1460, Fax. 703-993-1491