Can nanoflare heating define the coronal loop size?

Abstract:

The idea of nanoflare heating first coined by T. Gold (1964) and further developed by E. Parker (1972) has resulted in a dramatic paradigm shift in our understanding of the Sun, by emphasizing the critical role of the microscale physics in the formation of huge coronal structures such as coronal loops. Nanoflares are small, short-living energy conversion events in which the magnetic free energy is efficiently converted into heat. While the outcome of a single nanoflare is negligibly small, their cooperative contribution to the bulk coronal heating can be enormous. In this talk, we present recent advances in the numerical modeling of the nanoflare heating process. Our simulations demonstrate that densely distributed nanoflare events occur naturally inside a topologically complex coronal loop energized by photospheric vortices. These events lead to a formation of visible loops of various sizes, with the largest loop size imposed by the photospheric convection pattern and the smaller-scale loops reflecting clusters of nanoflares. Observational implications of our findings will be discussed.