Formation and plasma circulation of solar prominences

TL;DR

This paper uses 3D simulations to explore how solar prominences form and maintain plasma circulation, revealing a dynamic cycle of evaporation, condensation, and drainage consistent with observations.

Contribution

It introduces a detailed 3D model demonstrating the plasma cycle in prominences driven by in-situ condensations and plasma flows, clarifying longstanding uncertainties.

Findings

Prominence plasma forms via continuous condensation from the corona.

Plasma circulation involves evaporation from the chromosphere, condensation, and drainage.

Simulated images closely match actual solar observations.

Abstract

Solar prominences are long-lived cool and dense plasma curtains in the hot and rarefied outer solar atmosphere or corona. The physical mechanism responsible for their formation and especially for their internal plasma circulation has been uncertain for decades. The observed ubiquitous down flows in quiescent prominences are difficult to interpret as plasma with high conductivity seems to move across horizontal magnetic field lines. Here we present three-dimensional numerical simulations of prominence formation and evolution in an elongated magnetic flux rope as a result of in-situ plasma condensations fueled by continuous plasma evaporation from the solar chromosphere. The prominence is born and maintained in a fragmented, highly dynamic state with continuous reappearance of multiple blobs and thread structures that move mainly downward dragging along mass-loaded field lines. The prominence plasma circulation is characterized by the dynamic balance between the drainage of prominence plasma back to the chromosphere and the formation of prominence plasma via continuous condensation. Plasma evaporates from the chromosphere, condenses into the prominence in the corona, and drains back to the chromosphere, establishing a stable chromosphere-corona plasma cycle. Synthetic images of the modeled prominence with the Solar Dynamics Observatory Atmospheric Imaging Assembly closely resemble actual observations, with many dynamical threads underlying an elliptical coronal cavity.