Objective lagrangian vortex detection in the solar photosphere
Date
2018
Authors
Silva, S.
Rempel, E.
Gomes, T.
Requerey, I.
Chian, A.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Astrophysical Journal Letters, 2018; 863(1):L2-1-L2-7
Statement of Responsibility
Suzana de Souza e Almeida Silva, Erico Luiz Rempel, Tiago Francisco Pinheiro Gomes, Iker S. Requerey, Abrahamm C.-L. Chian
Conference Name
Abstract
Vortices in the solar photosphere can be linked to a wide range of events, such as small-scale solar eruptions, wave excitation, and heating of the upper part of the solar atmosphere. Despite their importance in solar physics, most of the current studies on photospheric vortices are based on methods that are not invariant under time-dependent translations and rotations of the reference frame and are Eulerian; i.e., they are based on single snapshots of a velocity field and, therefore, do not convey information on the true long-term motion of fluid particles on a time-varying field. Another issue with methods for vortex detection is that typically they provide false identifications in highly compressible flows. This Letter presents a novel criterion that effectively removes wrong detections based on the geometry of the streamlines of the displacement vector of fluid elements and can be readily applied to other astrophysical flows. The new criterion is applied to the Lagrangian-averaged vorticity deviation (LAVD), which is a recently developed frame invariant vortex detection method. The advantage of LAVD is that it delimits the vortices' outer boundaries precisely by following up the trajectories of fluid elements in space and time. The proposed method is compared with two other techniques using horizontal velocity fields extracted from Hinode satellite data.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2018. The American Astronomical Society. All rights reserved.