First Detection of Plasmoids from Breakout Reconnection on the Sun

Abstract

Transient collimated plasma ejections (jets) occur frequently throughout the solar corona, in active regions, quiet Sun, and coronal holes. Although magnetic reconnection is generally agreed to be the mechanism of energy release in jets, the factors that dictate the location and rate of reconnection remain unclear. Our previous studies demonstrated that the magnetic breakout model explains the triggering and evolution of most jets over a wide range of scales, through detailed comparisons between our numerical simulations and high-resolution observations. An alternative explanation, the resistive-kink model, invokes breakout reconnection without forming and explosively expelling a flux rope. Here we report direct observations of breakout reconnection and plasmoid formation during two jets in the fan-spine topology of an embedded bipole. For the first time, we observed the formation and evolution of multiple small plasmoids with bidirectional flows associated with fast reconnection in 3D breakout current sheets in the solar corona. The first narrow jet was launched by reconnection at the breakout current sheet originating at the deformed 3D null, without significant flare reconnection or a filament eruption. In contrast, the second jet and release of cool filament plasma were triggered by explosive breakout reconnection when the leading edge of the rising flux rope formed by flare reconnection beneath the filament encountered the preexisting breakout current sheet. These observations solidly support both reconnection-driven jet models: the resistive kink for the first jet, and the breakout model for the second explosive jet with a filament eruption.

A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)

“…Reeves, McCauley, and Tian (2015) find a brightening under the prominence before the eruption, suggesting that a tether-cutting mechanism is responsible for initiating the eruption (top-right). An alternate interpretation is given by Kumar et al (2019). The pre-eruption configuration of the filament and coronal rain in the 2796 Å channel (bottom-left) shows the ends of the filament (F and F ) and a null point (N).…”

“…Another possible eruption trigger is break-out reconnection, where reconnection high in the corona destabilizes a sheared magnetic field, causing an eruption. Break-out reconnection has been identified as the trigger for a small eruption at the limb based on bi-directional flows and small blobs observed in IRIS slit-jaw images (Kumar et al, 2019). However, other authors attribute the triggering of this eruption to tether cutting, based on the identification of brightenings seen in the slit-jaw images that occur just as the fast rise phase of the eruption begins (Reeves, McCauley, and Tian, 2015, Figure 27).…”

Onset of Turbulent Fast Magnetic Reconnection Observed in the Solar Atmosphere

“…Observations of solar bursts, jets and flares in (extreme) UV radiation show plasmoid-like blobs (e.g. Rouppe van der Voort et al 2017;Kumar et al 2019;Zhang & Ni 2019). However, due to the lack of magnetic field measurements in those observed blobs, their exact nature and direct connection to fast reconnection, particularly in naturally 3D systems, is unclear (Lin et al 2015;Ni et al 2017;Young et al 2018).…”

The Solar Orbiter mission

“…According to this model, the most likely source of the slow wind is a network of narrow, possibly singular corridors of open magnetic field in the surrounding closed-field corona. These map to a web of separatrices (S-web) and quasi-separatrix layers in the heliosphere, and the model proposes that the process that releases coronal plasma into the solar wind would have to be either the opening of closed magnetic flux, or interchange reconnection between open and closed magnetic field lines (Karpen et al 2016;Kepko et al 2016;Kumar et al 2019;Owens et al 2020). Closed magnetic field lines close to the Sun confine the plasma in loops where the compositional differentiation occurs, but these are continuously destroyed when neighbouring open field lines are advected into them.…”