Observed and simulated power spectra of kinetic and magnetic energy retrieved with 2D inversions

¹ Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
e-mail: danilovic@mps.mpg.de
² High Altitude Observatory, NCAR, PO Box 3000, Boulder, CO 80307, USA

Received: 8 December 2015
Accepted: 18 July 2016

Abstract

Context. Information on the origin of internetwork magnetic field is hidden at the smallest spatial scales.

Aims. We try to retrieve the power spectra with certainty to the highest spatial frequencies allowed by current instrumentation.

Methods. To accomplish this, we use a 2D inversion code that is able to recover information up to the instrumental diffraction limit.

Results. The retrieved power spectra have shallow slopes that extend further down to much smaller scales than has been found before. They do not seem to show any power law. The observed slopes at subgranular scales agree with those obtained from recent local dynamo simulations. Small differences are found for the vertical component of kinetic energy that suggest that observations suffer from an instrumental effect that is not taken into account.

Conclusions. Local dynamo simulations quantitatively reproduce the observed magnetic energy power spectra on the scales of granulation down to the resolution limit of Hinode/SP, within the error bars inflicted by the method used and the instrumental effects replicated.