Nature of turbulent transport across sheared zonal flows: insights from gyrokinetic simulations Articles uri icon


  • NEWMAN, D.E.
  • DECYK, V.K.

publication date

  • July 2011

start page

  • 1

end page

  • 10


  • 7(074018)


  • 53

International Standard Serial Number (ISSN)

  • 0741-3335

Electronic International Standard Serial Number (EISSN)

  • 1361-6587


  • Invited Paper to the ICCP-LAWP Conference, Santiago, Chile, August 2010. The traditional view regarding the reduction of turbulence-induced transport across a stable sheared flow invokes a reduction of the characteristic length scale in the direction perpendicular to the flow as a result of the shearing and stretching of eddies caused by the differential pull exerted in the direction of the flow. A reduced effective transport coefficient then suffices to capture the reduction, that can then be readily incorporated into a transport model. However, recent evidence from gyrokinetic simulations of the toroidal ion-temperature-gradient mode suggests that the dynamics of turbulent transport across sheared flows changes in a more fundamental manner, and that the use of reduced effective transport coefficients fails to capture the full dynamics that may exhibit both subdiffusion and non-Gaussian statistics. In this contribution, after briefly reviewing these results, we propose some candidates for the physical mechanisms responsible for endowing transport with such non-diffusive characteristics, backing these proposals with new numerical gyrokinetic data.