Observational Analysis of the Relation between Coronal Loop Heating and Photospheric Magnetic Fields

Yukio Katsukawa

The solar corona and the photosphere are linked through magnetic field lines, and heating energy is supposed to be supplied from the footpoints of each coronal loop alog magnetic field lines. Thus it is important to examine properties of photospheric magnetic fields at the footpoints of the coronal loops in order to understand heating of the coronal loops. We performed simultaneous observations of photospheric magnetic properties and coronal loop structures with Advanced Stokes Polarimeter (ASP) and TRACE. We found that (1) the difference between hot and cool coronal loops was related with number density of elemental magnetic elements at the loop footpoints in the photosphere (Katsukawa and Tsuneta 2005), and (2) the cool coronal loops emanating from a sunspot had their footpoints at the positions where there was highly interlaced magnetic structure around an umbra (Katsuakwa et al. 2005). These observational results suggest that critical magnetic properties are not yet spatially resolved to understand the coronal heating. Solar-B will provide an opportunity to perform direct investigation of the correlation between fine magnetic structures located at loop footpoints.

Correspondence

Yukio Katsukawa (yukio.katsukawa@nao.ac.jp), National Astronomical Observatory of Japan

presentation

invited