Explosive Events Associated With a Surge

Abstract

The solar atmosphere contains a wide variety of small-scale transient features. Here, we explore the interrelation between some of them such as surges, explosive events, and blinkers via simultaneous spectral and imaging data taken with the TRACE imager, the SUMER and Coronal Diagnostics Spectrometer (CDS) on board SOHO, and Swedish Vacuum Solar Telescope La Palma. The features were observed in spectral lines with formation temperatures from 10,000 K to 1 MK and with the TRACE Fe ix/x 171 Å filter. The Hα filtergrams were taken in the wings of the Hα 6365 Å line at ±700 mÅ and ±350 mÅ. The alignment of all data in both time and solar XY shows that SUMER line profiles, which are attributed to explosive events, are due to a surge phenomenon. The surge's up-and downflows, which often appear simultaneously, correspond to the blue-and redshifted emission of the transition region N v 1238.82 Å and O v 629.77 Å lines as well as radiance increases of the C i, S i, and S ii and Si ii chromospheric lines. Some parts of the surge are also visible in the TRACE 171 Å images which could suggest heating to coronal temperatures. The surge is triggered, most probably, by one or more Elerman bombs which are best visible in Hα ± 350 Å but were also registered by TRACE Fe ix/x 171 Å and correspond to a strong radiance increase in the CDS Mg ix 368.07 Å line. With the present study, we demonstrate that the division of small-scale transient events into a number of different subgroups, for instance explosive events, blinkers, spicules, surges or just brightenings, is ambiguous, implying that the definition of a feature based only on either spectroscopic or imaging characteristics as well as insufficient spectral and spatial resolution can be incomplete.

Comparative Analysis of a Transition Region Bright Point with a Blinker and Coronal Bright Point Using Multiple EIS Emission Lines

“…The work presented here has indicated that similar measurements made across multiple event classes, i.e., TR BP, blinker, and CBP, hold class-predictive power. Thereby, our work can be used in conjunction with similar studies (Chae et al, 2000;Harrison et al, 2003;Brković and Peter, 2004;Bewsher et al, 2005;Madjarska, Doyle, and De Pontieu, 2009) to begin facilitating a pathway which ultimately works towards automated multi-class classification of compact transients occurring in all temperature regimes of the solar atmosphere. As noted previously, this will be a major challenge of solar physics in the coming years.…”

Spectroscopic evidence for helicity in explosive events

“…Madjarska & Doyle (2003) tried to establish a relationship with limb phenomena that are observed with a different geometry, and suggested that blinkers (as observed by CDS) are the on-disk signature of spicules. While in this article the authors still assume that blinkers and EEs are two separate phenomena not directly related to or triggering each other, they later (Madjarska et al 2009) Wilhelm (2000) argues that there seems to be no obvious distinction between macrospicules and other spicules, apart from the fact that macrospicules are restricted to coronal hole locations. With this proposition, Madjarska et al (2006) conclude A&A 532, L9 (2011) that blinkers, EEs and macrospicules are indeed identical phenomena that are observed with different instruments and with a different geometry.…”

Chromospheric magnetic reconnection caused by photospheric flux emergence: implications for jet-like events formation

“…Some of the observed features are the result of spicules and/or macrospicules (Madjarska & Doyle 2003;Madjarska et al 2006), while others are the result of high velocity flows in small loops (Teriaca et al 2004). In more recent work, Madjarska et al (2009) presented observational data relating explosive events to a surge and demonstrated that the division of small-scale transient events into a number of different subgroups, for instance explosive events, blinkers, spicules, surges or just brightenings, is ambiguous, implying that the definition of a feature based only on either spectroscopic or imaging characteristics as well as insufficient spectral and spatial resolution can be incomplete.…”