Self-Regulation of Solar Coronal Heating Process via Collisionless Reconnection Condition

TL;DR

This paper presents a new paradigm for solar coronal heating as a self-regulating process that maintains plasma near a marginally collisionless state through cyclical reconnection and evaporation events.

Contribution

It introduces a novel self-regulation model linking plasma density, reconnection regimes, and energy release cycles in the solar corona.

Findings

Coronal density fluctuates around a critical level.

Heating occurs via cycles of nano-flares and evaporation.

The model explains observed coronal plasma conditions.

Abstract

I propose a new paradigm for solar coronal heating viewed as a self-regulating process keeping the plasma marginally collisionless. The mechanism is based on the coupling between two effects. First, coronal density controls the plasma collisionality and hence the transition between the slow collisional Sweet-Parker and the fast collisionless reconnection regimes. In turn, coronal energy release leads to chromospheric evaporation, increasing the density and thus inhibiting subsequent reconnection of the newly-reconnected loops. As a result, statistically, the density fluctuates around some critical level, comparable to that observed in the corona. In the long run, coronal heating can be represented by repeating cycles of fast reconnection events (nano-flares), evaporation episodes, and long periods of slow magnetic stress build-up and radiative cooling of the coronal plasma.