Hi-C2.1 Observations of Solar Jetlets at Edges of Network Lanes

Abstract

We present high resolution (0.2) high cadence (5s) extreme ultraviolet (EUV) observations of small-scale jetlet-like features and spicule-like features observed with NASAs High-resolution Coronal Imager2.1 (Hi-C) during its 5min observing span. We investigate the magnetic setting of 4 on-disk jetlets and 2 on-disk spicules by using high resolution 172A images from Hi-C and EUV images from Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and line-of-sight magnetograms from SDO/Helioseismic and Magnetic Imager (HMI). The jetlets and spicules are at edges of magnetic network lanes. From magnetograms co-aligned with the Hi-C and AIA images, we find that the jetlets stem from sites of likely flux cancelation between merging majority-polarity and weaker minority-polarity flux, but in contrast to larger jetlets observed by IRIS some do not show obvious enhanced brightenings at their base. Based on the similarity of these observations of approx. 4 obvious Hi-C small jetlets with our previous observations of 10 IRIS larger jetlets and approx. 30 coronal jets in quiet regions and coronal holes, we infer that flux cancelation is probably the essential process in the buildup and triggering of jetlets. Our observations suggest that network jetlet eruptions, large and small, are small-scale analogs of both larger-scale coronal jet eruptions and the still-larger-scale eruptions that makemajor CMEs. For simplicitywe will use termjetlets for jetlet-like features and spicules for spicule-like features