An Observational Test That Disproves Coronal Nanoflare Heating Models

Abstract

All theoretical models of nanoflare heating in the solar corona predict loops with an unresolved multistrand structure, which is in discrepancy with the quasi-isothermal cross sections of the finest coronal loop structures observed with TRACE, which have spatially resolved widths of w ≈ 1000–2000 km. We suggest modifying the theoretical models by relocating the hypothetical nanoflare events from their coronal location down to the chromosphere/transition region.