Excitation of an outflow from the lower solar atmosphere and a co-temporal EUV transient brightening

Abstract

We analyse an absorption event within the H$\alpha$ line wings, identified as a surge, and the co-spatial evolution of an EUV brightening, with spatial and temporal scales analogous to a small blinker. We conduct a multi-wavelength, multi-instrument analysis using high-cadence, high-resolution data, collected by the Interferometric BIdimensional Spectrometer on the Dunn Solar Telescope, as well as the space-borne Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager instruments onboard the Solar Dynamics Observatory. One large absorption event situated within the plage region trailing the lead sunspot of AR 11579 is identified within the H-alpha line wings. This event is found to be co-spatially linked to a medium-scale (around 4 arcseconds in diameter) brightening within the transition region and corona. This ejection appears to have a parabolic evolution, first forming in the H-alpha blue wing before fading and reappearing in the H-alpha red wing, and comprises of a number of smaller fibril events. The line-of-sight photospheric magnetic field shows no evidence of cancellation leading to this event. Our research has identified clear evidence that at least a subset of transient brightening events in the transition region are linked to the influx of cooler plasma from the lower solar atmosphere during large eruptive events, such as surges. These observations agree with previous numerical researches on the nature of blinkers and, therefore, suggest that magnetic reconnection is the driver of the analysed surge events; however, further research is required to confirm this.