NSF Org:	AGS Division of Atmospheric and Geospace Sciences
Recipient:	COLORADO STATE UNIVERSITY
Initial Amendment Date:	April 15, 1998
Latest Amendment Date:	January 19, 2000
Award Number:	9729970
Award Instrument:	Continuing Grant
Program Manager:	Sumant Nigam AGS  Division of Atmospheric and Geospace Sciences GEO  Directorate for Geosciences
Start Date:	March 15, 1998
End Date:	February 28, 2001 (Estimated)
Total Intended Award Amount:	$383,614.00
Total Awarded Amount to Date:	$383,614.00
Funds Obligated to Date:	FY 1998 = $123,950.00 FY 1999 = $127,837.00 FY 2000 = $131,827.00
History of Investigator:	Wayne Schubert (Principal Investigator) waynes@atmos.colostate.edu
Recipient Sponsored Research Office:	Colorado State University 601 S HOWES ST FORT COLLINS CO  US  80521-2807 (970)491-6355
Sponsor Congressional District:	02
Primary Place of Performance:	Colorado State University 601 S HOWES ST FORT COLLINS CO  US  80521-2807
Primary Place of Performance Congressional District:	02
Unique Entity Identifier (UEI):	LT9CXX8L19G1
Parent UEI:
NSF Program(s):	LARGE-SCALE DYNAMIC METEOROLOG
Primary Program Source:	app-0100  app-0198  app-0199
Program Reference Code(s):	0000, OTHR
Program Element Code(s):	152700
Award Agency Code:	4900
Fund Agency Code:	4900
Assistance Listing Number(s):	47.050

ABSTRACT

This award provides support for a systematic study of the minimum enstrophy principle and maximum entropy principle as they apply to problems of potential vorticity mixing in hurricanes and larger-scale tropical circulations. Within the context of a barotropic, nondivergent model, theoretical predictions will be extended from the symmetric to the asymmetric case. Of particular interest will be the determination of the bifurcations between the symmetric and asymmetric structures predicted by the maximum entropy vortex arguments. The results of such an asymmetric theory should reveal what kind of steady state asymmetric features are possible in hurricanes. Outside the context of the non-divergent model, both direct numerical integrations and theoretical predictions will be generalized to the shallow water equations (on the plane and on the sphere). This generalization will allow a distinction between vorticity and potential vorticity and a distinction between enstrophy and potential enstrophy, and will allow the energy constraint to include both kinetic and potential energy. The generalization to the quasi-static primitive equations in isentropic coordinates should then follow from the shallow water case. Each step in this investigation will help to improve understanding (and, ultimately, prediction) of the nonlinear evolution of large-scale atmospheric flows.

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