Spectroscopic and Stereoscopic Observations of the Solar Jets

We present a comprehensive study of a series of recurrent jets that occurred at the periphery of the NOAA active region 12114 on 2014 July 7. These jets were found to share the same source region and exhibited rotational motions as they propagated outward. The multiwavelength imaging observations made by the AIA and IRIS telescopes reveal that some of the jets contain cool plasma only, while some others contain not only cool but also hot plasma. The Doppler velocities calculated from the IRIS spectra show a continuous evolution from blue-to redshifts as the jet motions change from upward to downward. Additionally, some jets exhibit opposite Doppler shifts on both their sides, indicative of rotating motions along their axes. The inclination angle and three-dimensional velocity of the largest jet were inferred from the imaging and spectroscopic observations, which show high consistency with those derived from the stereoscopic analysis using dual-perspective observations by SDO/AIA and STEREO-B/EUVI. By relating the jets to the local UV/EUV and full-disk GOES X-ray emission enhancements, we found that the previous five small-scale jets were triggered by five bright points while the last/largest one was triggered by a C1.6 solar flare. Together with a number of type III radio bursts generated during the jet eruptions as well as a weak CME that was observed in association with the last jet, our observations provide evidence in support of multiscale magnetic reconnection processes being responsible for the production of jet events.