Travel grant for observing with SST, La Palma- Dynamic events in the chromosphere of coronal holes: RBE's and Swirls

One of the most intriguing problems of modern plasma-astrophysics is the rapid rise of temperature in the magnetised solar atmosphere. It is now clear that part of the vast mechanical energy of sub-photospheric granular motions is channelled into the solar atmosphere (see e.g. our Nature paper, Wedemeyer-Bhom et al. 2012 on how this energy transport takes space in solar tornadoes), where it is dissipated leading to the enormous heating of ambient plasma to millions of K. The details of this energy transport is not yet fully understood. Since the solar atmosphere has a large variety of features, from spicules, fibrils, pores, sunspot, coronal loops, coronal holes, etc. the energisation may be different in each of them. Cardinal questions are: do magnetohydrodynamic (MHD) waves play a key role, or is it the build-up and rapid release of magnetic stresses? Magnetic field is very central in shaping the solar atmosphere because: it (i) not only outlines the MHD waveguides that act as channels for the energy to propagate but, it also (ii) determines connectivity topology; and (iii) stores energy relevant to plasma heating.

A viable scenario of this energy channelling is that the both coherent and random (sub)photospheric motions excite MHD waves that sail through the magnetised solar atmosphere, while carrying and damping the necessary of non-thermal energy relevant in the magnetic structures of the solar atmosphere. It is not anymore a question whether MHD waves are there. Instead, focus is now on how the necessary wave flux needed towards plasma heating is present in the magnetised plasma structures and what type of MHD waves are the major players in the energy transport process(es).

Here we propose
(i) observing and comprehensive tracking MHD waves from photosphere to chromosphere in localised highly dynamic magnetic waveguides with emphases on the magnetic signatures of these waves;
(ii) Next, we will determine the actual identity and nature of the detected MHD waves (slow, fast, Alfven; kink, sausage; surface, body; etc.);
(iii) We will investigate how these waves are present in a range of structures (e.g. a) spicules at limb; b) swirls in coronal holes)
(iv) We will build up statistics of these structures and the waves present therein