The National Science Foundation, under Grants ATM-9820233 and ATM-0215358, provided partial support for this research.
Bretherton, C. S., , and C. Schär, 1993: Flux of potential vorticity substance: A simple derivation and a uniqueness property. J. Atmos. Sci., 50 , 1834–1836.
Haynes, P. H., , and M. E. McIntyre, 1987: On the evolution of vorticity and potential vorticity in the presence of diabatic heating and frictional and other forces. J. Atmos. Sci., 44 , 828–841.
Marshall, J., , D. Jamous, , and J. Nilsson, 2001: Entry, flux, and exit of potential vorticity in ocean circulation. J. Phys. Oceanogr., 31 , 777–789.
Schär, C., , and D. R. Durran, 1997: Vortex formation and vortex shedding in continuously stratified flows past isolated topography. J. Atmos. Sci., 54 , 534–554.
Truesdell, C., 1951: Proof that Ertel's theorem holds on average for any medium suffering no tangential acceleration on the boundary. Geofis. Pura. Appl., 19 , 167–169.