CENTER FOR COMPUTATIONAL MATHEMATICS COLLOQUIUM

                  UNIVERSITY OF COLORADO AT DENVER



TITLE:   A semi-implicit semi-Lagrangian global circulation model
 

SPEAKER: Jeffrey S. Scroggs, Department of Mathematics, 
         North Carolina State University, Raleigh, NC
         

DATE:    Wednesday, March 12, 1997 (PLEASE NOTE UNUSUAL DAY)


PLACE:   Math Conference Room 626 
         UCD Building, 1250 14th St., Denver


TIME:    2:30 (Refreshments served at 2:15 pm) (PLEASE NOTE UNUSUAL TIME)



ABSTRACT

Global circulation models (GCMs) are used in numerical climate
simulations for predictions ranging from several months to several
centuries.  A semi-implicit semi-Lagrangian (SISL) GCM has been developed
at North Carolina State University.  The SISL approach permits the time
step to be chosen based on balancing temporal and spatial accuracy.  This
compares with more standard Eulerian discretization approaches that
must choose time steps several orders of magnitude smaller
based on a stability (CFL) restrictions.  This presentation will be
an overview of this SISL project, including the choice of a reference
state that permits topography, and some developments regarding
conservative semi-Lagrangian methods.  Graduate students and other
interested faculty are welcome to attend.