author = "Silva, Suzana de Souza e Almeida and Rempel, Erico Luiz and Gomes, 
                         Tiago Francisco Pinheiro and Requerey, Iker S. and Chian, Abraham 
                         Chian Long",
          affiliation = "{Instituto Tecnologico de Aeron{\'a}utica (ITA)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Max Planck Institute for Solar 
                         System Research}",
                title = "Objective Lagrangian Vortex Detection in the Solar Photosphere",
              journal = "Astrophysical Journal Letters",
                 year = "2018",
               volume = "863",
               number = "1",
                pages = "L2",
                month = "Aug.",
             keywords = "convection, methods: data analysis, Sun: granulation, Sun: 
             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 timevarying 
                         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.",
                  doi = "10.3847/2041-8213/aad180",
                  url = "http://dx.doi.org/10.3847/2041-8213/aad180",
                 issn = "2041-8205 and 2041-8213",
             language = "en",
           targetfile = "silva_objective.pdf",
        urlaccessdate = "29 nov. 2020"