[Todos] IAFE -SEMINARIOS:"A Survey of Topological Features of the Solar Corona ", Miercoles 12 de octubre 2011, 14hs.

[difusion en iafe.uba.ar]

 __________________________________________________________________

             Seminario de Física Solar y Plasmas Astrofísicos
                 Instituto de Astronomía y Física del Espacio
                           CONICET-UBA
 __________________________________________________________________

              "A Survey of Topological Features of the Solar Corona "

                                      Marc DeRosa
     Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA USA

                           Miercoles 12 de octubre 2011, 14hs.
                                Aula del Edificio IAFE

The topology of the solar coronal magnetic field has attracted much recent
interest, due to its importance in determining (for example) the sector
structure of the solar wind, the evolution of coronal hole boundaries, and
whether the configurations of coronae overlying active regions are
unstable and thus possibly eruption-prone. Software that identifies the
topological skeleton (null points, spine lines, separators, and separatrix
surfaces) of a spherical vector field in three dimensions has been applied
to a long-running time series of potential-field source-surface (PFSS)
models of the solar corona. We identify the skeletons for a selection of
dates spanning the SOHO, STEREO, and SDO eras, and provide visualizations
of these topological features in three dimensions. The selected fields
contain several topological features of interest, including exceedingly
narrow channels of open field and separators associated with inferred
reconnection sites, and evidence of the coronal origins of streamers and
pseudostreamers in the heliosphere. Such topological features appear
frequently in potential field models of the magnetic corona, thus implying
that the actual solar corona is likely to involve even more complex
topologies, especially as its dynamics and evolution are taken into
account