Magnetic Flux Cancellation as the Trigger Mechanism of Solar Coronal Jets

Abstract

Coronal jets are transient narrow features in the solar corona that originate from all regions of the solar disk: active regions, quiet sun, and coronal holes. Recent studies indicate that at least some coronal jets in quiet regions and coronal holes are driven by the eruption of a minifilament (Sterling et al. 2015) following flux cancellation at a magnetic neutral line (Panesar et al. 2016). We have tested the veracity of that view by examining 60 random jets in quiet regions and coronal holes using multithermal (304Å, 171Å, 193Å, and 211Å) extreme ultraviolet (EUV) images from the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and line-of-sight magnetograms from the SDO/Helioseismic and Magnetic Imager (HMI). By examining the structure and changes in the magnetic field before, during, and after jet onset, we found that 85% of these jets resulted from a minifilament eruption triggered by flux cancellation at the neutral line. The 60 jets have a mean base diameter of 8800 ± 3100 km and a mean duration of 9 ± 3.6 minutes. These observations confirm that minifilament eruption is the driver and magnetic flux cancellation is the primary trigger mechanism for most coronal hole and quiet region coronal jets.

Hi-C 2.1 Observations of Jetlet-like Events at Edges of Solar Magnetic Network Lanes

“…To examine the magnetic field evolution quantitatively, we measured the minority-polarity flux patch of the base region that is bounded by a yellow box region of Figure 2n. Figure 4a shows a decrease in that positive flux between 18:57:37 and 19:00:37UT, presumably from flux cancelation that may have triggered the eruption of the jetlet-like event 1, as in larger jetlets and coronal jets examined by Panesar et al (2016bPanesar et al ( , 2018a and by McGlasson et al (2019). This event is similar to IRIS jetlets (Panesar et al 2018b) in that the jetlets also occurred at the edges of network flux lanes at canceling neutral lines.…”

Solar Jets: SDO and IRIS Observations in the Perspective of New MHD Simulations

“…Several studies show clearly that tiny coronal jets in coronal holes and quiet Sun are due to flux cancellation (Savcheva et al, 2007;Panesar et al, 2016b, Panesar et al, 2017, Panesar et al, 2018aMcGlasson et al, 2019). In coronal holes, converging flows toward the boundary of super-granule with mixed polarities leading to cancelling flux was found to be a favorable solution to explain the onset of jets (Young and Muglach, 2014;Muglach, 2021).…”

Observation and modelling of solar jets

“…Panesar et al [98] argued that the reason for flux emergence not directly causing jets is because the speed of emergence is seldom, if ever, fast enough. The emerging-reconnection scenario was challenged by the discovery of blowout jets that often involve the eruption of mini-filaments or filament channels [36,62,63,69,97] in association with flux cancellations [44,66,68,247,[304][305][306][307][308], and the cool component of blowout jets is actually the erupting filament material itself [44,63,69] rather than chromospheric material carried up by the emerging flux and accelerated by the show the direction of movement of the magnetic field lines, and features including the X-point, slow and fast shocks, and cool and hot jets are indicated [140].…”

“…Panesar et al [98] argued that the reason for flux emergence not directly causing jets is because the speed of emergence is seldom, if ever, fast enough. The emerging-reconnection scenario was challenged by the discovery of blowout jets that often involve the eruption of mini-filaments or filament channels [36,62,63,69,97] in association with flux cancellations [44,66,68,247,304–308], and the cool component of blowout jets is actually the erupting filament material itself [44,63,69] rather than chromospheric material carried up by the emerging flux and accelerated by the magnetic tension force as proposed in the emerging-reconnection model [129]. In a statistical study of 27 equatorial coronal hole jets, Kumar et al [97] found that six jets (22%) were apparently associated with flux cancellations, while the remaining events did not show measurable flux emergence or cancellation associated with the eruption.…”