Coupling between convection and magnetic field in filament channel |
Auteur | Schmieder Brigitte |
Institution | LESIA |
Thème | Theme3 |
| Auteur(s) supplémentaire(s) | Roudier T.**, Mein N.*, Mein P.* , Chandra R.*** |
| Institution(s) supplémentaire(s) | ** IRAP, Toulouse, France, *** Kumaun University, Nainital, India |
|
Abstract | The analysis of the proper motions using SDO/HMI continuum images with the new version of the coherent structure tracking (CST) algorithm
developed to track the granules as well as the large scale photospheric flows, was perfomed during three hours in a region containing a large filament
channel on September 17, 2010.
Supergranules were idenfied in the filament channel. Diverging flows inside the supergranules are similar in and out the filament channel. Using corks,
we derived the passive scalar points and produced maps of cork distribution. The anchorage structures with the photosphere (feet) of the filament are
located in the areas of converging flows with accumulations of corks. Averaging the velocity vectors for each latitude we defined a profile of the
differential rotation.
We conclude that the coupling between the convection and magnetic field in the photosphere is relatively strong. The filament experienced the
convection motions through its feet. On a large scale point-of-view the differential rotation induced a shear of 0.1 km/s in the filament. On a small scale
point-of-view convection motions favored the interaction/cancellation of the parasitic polarities at the base of the feet with the surrounding network
explaining the brightenings,/jets and the eruption that were observed in the EUV filament.
|
