@article{ISI:000286986000002,
 abstract = {We present a natural framework for studying the persistence problem in
two-dimensional fluid turbulence by using the Okubo-Weiss parameter
Lambda to distinguish between vortical and extensional regions. We then
use a direct numerical simulation of the two-dimensional, incompressible
Navier-Stokes equation with Ekman friction to study probability
distribution functions (PDFs) of the persistence times of vortical and
extensional regions by employing both Eulerian and Lagrangian
measurements. We find that, in the Eulerian case, the persistence-time
PDFs have exponential tails; by contrast, this PDF for Lagrangian
particles, in vortical regions, has a power-law tail with an exponent
theta = 2.9 +/- 0.2.},
 article-number = {054501},
 author = {Perlekar, Prasad and Ray, Samriddhi Sankar and Mitra, Dhrubaditya and
Pandit, Rahul},
 doi = {10.1103/PhysRevLett.106.054501},
 issn = {0031-9007},
 journal = {PHYSICAL REVIEW LETTERS},
 month = {FEB 3},
 number = {5},
 times-cited = {28},
 title = {Persistence Problem in Two-Dimensional Fluid Turbulence},
 unique-id = {ISI:000286986000002},
 volume = {106},
 year = {2011}
}