Towards Understanding the Initiation and Acceleration of Coronal Jets

Coronal jets are energetic, small-scale eruptions characterized by a culminated spire, bright dome-shaped base, and magnetic flux emergence, cancellation or other notable changes in photopsheric flux. Although coronal jets, specifically, EUV and X-ray jets, have been studied extensively, a complete picture of their initiation and acceleration mechanisms has not been found. Current models of jets present informal categories based loosely on their morphology, and speculation on the location of magnetic reconnection. Namely, 'standard' jets, are associated with narrow spires, simple magnetic topologies, and are thought to form via external reconnection, when one polarity region emerges or cancels with a flux region of the opposite polarity. Conversely, blow-out jets are thought to form when internal reconnection (with or without external reconnection) frees tightly wound flux tubes, via tether-cutting reconnection, causing a much more complex eruption of cool and warm plasma. In each of these scenarios, erupting jet plasma can be accelerated by a number of different mechanisms working in tandem or independently. In this talk, I will discuss recent efforts to determine the acceleration mechanism of coronal jets using a combination of observations and Non-linear Force-Free Field (NLFFF) models. We use observations from Hinode's X-ray Telescope (XRT), Solar Dynamics Observatory's Atmospheric Imaging Array (AIA), and the Interface Region Imaging Spectrograph (IRIS) to examine velocity as a function of temperature for selected jets to determine if chromospheric evaporation attributes to the jet acceleration. We also investigate the magnetic topological evolution of several coronal jets containing sigmoid-like flux ropes using a NLFFF model obtained with the flux rope insertion method and magneto-frictional relaxation. In this work, we show that multiple mechanisms may be responsible for the acceleration of coronal jets and that the combination of observational tests and magnetic modeling are useful in understanding their complex formation.