Models of anomalous transport: From Tokamaks to atmosphere
Overview:
In this subproject we investigate numerically, using Hamiltonian models, diffusion, dispersion and mixing of particles in a magnetically confined plasma of tokamaks and aerosols in the atmosphere. One of our main goals is to built a bridge between this two cases concentrating on an unified description of anomalous transport.
For the plasma confined in tokamaks, the radial transport of particles appears due to electrostatic fluctuations and the numerical study is done using a model of drift waves proposed in [Horton, 1985] and discussed in [Marcus, 2008]. For this case, we are interested in investigate how diffusion and dispersion vary with time, how this quantities are related to mixture and how mixture is induced by the existence of coherent structures in the flow [Haller, 2000].
In order to study the movement of aerosols in the atmosphere, a model proposed in [Negrete, 1993] for the Rossby waves is used. This waves arise due to Coriolis forces in the atmosphere. In this model we can see chains of island with convective flow of particles which, in turn, generate diffusion, dispersion and mixing similar to the model for plasma.
Members:
- Prof. Dr. Iberê L. Caldas, USP São Paulo, Brazil
- Prof. Dr. Igor M. Sokolov, HU Berlin, Germany
- Rafael O. Suigh, PhD-student, USP São Paulo, Brazil
References:
[Horton,1985] W. Horton. “Onset of stochasticity and the diffusion approximation in drift waves”. Plasma Physics and Controlled Fusion 27, 937 (1985).
[Marcus, 2008] F. A. Marcus, I. L. Caldas, Z. O. Guimarães-Filho, P. J. Morrison, W. Horton, Yu. K. Kuznetsov, and I. C. Nascimento. “Reduction of Chaotic Particle Transport Driven by Drift Waves in Sheared Flows”. Physics of Plasmas 15, 112304 (2008).
[Haller, 2000] G. Haller and G. Yuan. “Lagrangian Coherent Structures and Mixing in Two-Dimensional Turbulence”. Physica D, 147, 352 (2000).
[Negrete, 1993] D. del-Castillo-Negrete and P. J. Morrison. “Chaotic transport by Rossby waves in shear flow”. Physics of Fluids A 5, 948 (1993).
[Boffetta, 2002] G. Boffetta and I.M. Sokolov. “Statistics of two-particle dispersion in two-dimensional turbulence”. Physics of Fluids 14, 3224 (2002).