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On The Persistence Of Small Regions Of Vorticity In The Protoplanetary Nebula, S. S. Davis, D. P. Sheehan, J. N. Cuzzi
On The Persistence Of Small Regions Of Vorticity In The Protoplanetary Nebula, S. S. Davis, D. P. Sheehan, J. N. Cuzzi
Physics and Biophysics: Faculty Scholarship
The fate of small regions of vorticity in a barotropic model of the protoplanetary nebula is investigated over thousands of years using a finite difference model. It is found that the coherence time for a small island of vorticity depends on its size, strength, orientation, and radial location in the nebula. Anticyclonic vorticity retains its coherence for longer times than cyclonic vorticity due to favorable interactions with the Keplerian shear flow. Rossby waves are generated as a result of mean vorticity gradients across the disk. The two-dimensional nebula evolves from discrete vortices into an axisymmetric flow consisting of small-amplitude vortex …
Reply To ‘‘Comment On ‘Dynamically Maintained Steady-State Pressure Gradients’ ’’, D. P. Sheehan
Reply To ‘‘Comment On ‘Dynamically Maintained Steady-State Pressure Gradients’ ’’, D. P. Sheehan
Physics and Biophysics: Faculty Scholarship
A reply is made to Duncan’s Comment [T. L. Duncan, Phys. Rev. E 61, 4661 (2000)] on my earlier paper [D. P. Sheehan, Phys. Rev. E 57, 6660 (1998)] in which he raises an apparent second-law paradox arising from dynamically maintained, steady-state pressure gradients. Resolutions to this paradox are considered in light of current theoretical and experimental understanding.