DETECTION OF COHERENT STRUCTURES IN PHOTOSPHERIC TURBULENT FLOWS

Abraham C.-L. Chian, Erico L. Rempel, Guillaume Aulanier, Brigitte Schmieder, Shawn C. Shadden, Brian T. Welsch, Anthony R. Yeates
2014 Astrophysical Journal  
We study coherent structures in solar photospheric flows in a plage in the vicinity of the active region AR 10930 using the horizontal velocity data derived from Hinode/SOT magnetograms. Eulerian and Lagrangian coherent structures are detected by computing the Q-criterion and the finite-time Lyapunov exponents of the velocity field, respectively. Our analysis indicates that, on average, the deformation Eulerian coherent structures dominate over the vortical Eulerian coherent structures in the
more » ... age region. We demonstrate the correspondence of the network of high magnetic flux concentration to the attracting Lagrangian coherent structures (a-LCS) in the photospheric velocity based on both observations and numerical simulations. In addition, the computation of a-LCS provides a measure of the local rate of contraction/expansion of the flow.
doi:10.1088/0004-637x/786/1/51 fatcat:oepzn4jp55dqpmi24erwadjxq4