An EUV Jet Driven by a Series of Transition Region Microjets

Jets are one of the most common eruptive events in the solar atmosphere, and they are believed to be important in the context of coronal heating and solar wind acceleration. We present an observational study on a sequence of jets with the data acquired with the Solar Dynamics Observatory and the Interface Region Imaging Spectrograph. This sequence is peculiar in that an extreme-ultraviolet (EUV) jet, ~29″ long and with a dome-like base, appears to be a consequence of a series of transition region (TR) microjets that are a few arcsecs in length. We find that the occurrence of any TR microjets is always associated with the change of geometry of microloops at the footpoints of the microjets. A bundle of TR flux ropes is seen to link a TR microjet to the dome-like structure at the base of the EUV jet. This bundle rises as a response to the TR microjets, with the rising motion eventually triggering the EUV jet. We propose a scenario involving a set of magnetic reconnections, in which the series of TR microjets are associated with the processes to remove the constraints to the TR flux ropes and thus allows them to rise and trigger the EUV jet. Our study demonstrates that small-scale dynamics in the lower solar atmosphere are crucial in understanding the energy and mass connection between the corona and the solar lower atmosphere, even though many of them might not pump mass and energy to the corona directly.