SMALL-SCALE JETS OBSERVED AT SITES OF FLUX CANCELATION

Solar jets of all sizes are magnetically channeled narrow eruptive events; the larger ones are often observed in the solar corona in EUV and coronal X-ray images. Recent observations show that the buildup and triggering of the minifilament eruptions that drive coronal jets result from magnetic flux cancelation under the minifilament, at the neutral line between merging majority-polarity and minority-polarity magnetic flux patches. Here we investigate the magnetic setting of on-disk small-scale jets (also known as jetlets) by using high resolution 172A images from the High-resolution Coronal Imager (Hi-C2.1) and EUV images from Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and UV images from Interface Region Imaging Spectrograph (IRIS) and line-of-sight magnetograms from SDO/Helioseismic and Magnetic Imager (HMI). We also use Hinode/SOT/FG magnetograms, along with AIA and IRIS images, whenever they are available. We observe jetlets at edges of magnetic network lanes. From magnetograms co-aligned with the Hi-C, IRIS, and AIA images, we find that the jetlets stem from sites of flux cancelation between merging majority-polarity and minority-polarity flux patches, and some of the jetlets show faint brightenings at their bases reminiscent of the base brightenings in coronal jets. Based on these observations of jetlets and our previous observations of ~30 coronal jets in quiet regions and coronal holes, we infer that flux cancelation is the essential process in the buildup and triggering of jetlets. Our observations suggest that network jetlet eruptions are small-scale analogs of both larger-scale coronal jet eruptions and the still-larger-scale eruptions that make major CMEs.