A STANDARD-TO-BLOWOUT JET

Abstract

The commonly observed jets provide critical information on the small-scale energy release in the solar atmosphere. We report a near disk-center jet on 2010 July 20, observed by the Solar Dynamics Observatory. In this event, the standard interchange magnetic reconnection between an emerging flux spanning 9 x 10^3 km and ambient open fields is followed by a blowout-like eruption. In the "standard" stage, as the emerging negative element approached the nearby positive network fields, a jet with a dome-like base in EUV grew for 30 minutes before the jet spire began to migrate laterally with enhanced flux emergence. In the "blowout" stage, the above converging fields collided and the subsequent cancellation produced a UV microflare lasting seven minutes, in which the dome of the jet seemed to be blown out as (1) the spire swung faster and exhibited an unwinding motion before vanishing, (2) a rising loop and a blob erupted leaving behind cusped structures, with the blob spiraling outward in acceleration after the flare maximum, and (3) ejecting material with a curtain-like structure at chromospheric to transition-region temperatures also underwent a transverse motion. It is thus suggested that the flare reconnection rapidly removes the outer fields of the emerging flux to allow its twisted core field to erupt, a scenario favoring the jet-scale magnetic breakout model as recently advocated by Moore et al. in 2010.