STITCH: A Subgrid-scale Model for Energy Buildup in the Solar Corona

The solar corona routinely exhibits explosive activity, in particular coronal mass ejections and their accompanying eruptive flares, that have global-scale consequences. These events smaller counterparts, jets, originate narrow, sinuous filament channels. key processes form evolve the channels operate on still spatial scales much longer time scales, culminating a vast separation of characteristic lengths times govern these phenomena. In this article, we describe implementation tests an efficient subgrid-scale model for generating structures magnetohydrodynamics (MHD) simulations. STITCH -- STatistical InjecTion Condensed Helicity is physics-based, reduced representation helicity condensation: process wherein small-scale vortical surface convection forms ubiquitous current sheets, pervasive reconnection across sheets mediates inverse cascade magnetic free energy, thereby forming abstracts complex into single new term, MHD Ohm's law induction equation, which directly injects tangential flux low corona. We show approach very good agreement with full helicity-condensation calculation treats all dynamics explicitly, while enabling substantial reductions temporal duration especially, but also resolution. addition, illustrate flexibility at localized energizing distributions boundaries. simple to implement computationally efficient, making it powerful technique event-based, data-driven modeling eruptions.