Flux emergence into the solar atmosphere: buoyancy instabilities, current sheets and reconnection

F. Moreno-Insertis

Numerical experiments concerning the emergence of magnetic flux into the solar atmosphere and the associated dynamical phenomena are now being routinely carried out thanks to the advances in MHD codes and the new supercomputation facilities in the world. In recent years, three-dimensional simulations of the process of eruption of magnetic flux from the solar interior into the corona have been carried out, albeit with strongly simplified assumptions concerning the thermodynamics and with limited resolution. Yet, many phenomena are being reproduced in the experiments that are amenable to a qualitative (to a limited extent, also quantitative) comparison with observations in the photosphere, chromosphere and corona. Also, the numerical experiments permit new insights into the theory of coronal and photospheric magnetic fields, including buoyancy instabilities and reconnection.
In this review, a summary of the history of the subject will be given together with a briev overview of relevant observations. A number of recent experiments of the interaction of the emerging fields with pre-existing coronal fields have been obtained by different groups and will be discussed. Particular attention will be given to the formation of current sheets, reconnection phenomena taking place in them and the emission of high-velocity jets. The availability of data from the Solar-B mission promises a new era in understanding flux emergence into the solar atmosphere: their importance will also be discussed as part of this review.

Correspondence

Fernando Moreno-Insertis (fmi@ll.iac.es), Instituto de Astrofisica de Canarias

presentation

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