Rapid Evolution of Type II Spicules Observed in Goode Solar Telescope On-Disk H-alpha Images

Abstract

We analyze ground-based chromospheric data acquired at a high temporal cadence of 2 s in wings of the H$\alpha$ spectral line using Goode Solar Telescope (GST) operating at the Big Bear Solar Observatory. We inspected a 30 minute long H$\alpha$-0.08~nm data set to find that rapid blue-shifted H$\alpha$ excursions (RBEs), which are a cool component of type II spicules, experience very rapid morphological changes on the time scales of the order of 1 second. Unlike typical reconnection jets, RBEs very frequently appear \textit{in situ} without any clear evidence of H$\alpha$ material being injected from below. Their evolution includes inverted "Y", "V", "N", and parallel splitting (doubling) patterns as well as sudden formation of a diffuse region followed by branching. We also find that the same feature may undergo several splitting episodes within about 1 min time interval.

11 pages, 4 figures

References in corpus (13)

• Chromospheric Anemone Jets as Evidence of Ubiquitous Reconnection
• Prevalence of Small-scale Jets from the Networks of the Solar Transition Region and Chromosphere
• Observing the Roots of Solar Coronal Heating - in the Chromosphere
• On the generation of solar spicules and Alfvénic waves
• Generation of Solar Spicules and Subsequent Atmospheric Heating
• An Interface Region Imaging Spectrograph first view on Solar Spicules
• Search for high velocities in the disk counterpart of type II spicules
• Statistical properties of the Disk Counterparts of Type II Spicules from simultaneous observations of RBEs in Ca II 8542 and Hα
• Revision of Solar Spicule Classification
• Generation of quasi-periodic waves and flows in the solar atmosphere by oscillatory reconnection
• The Dynamics of Rapid Redshifted and Blueshifted Excursions in the Solar Halpha line
• What causes the high apparent speeds in chromospheric and transition region spicules on the Sun?
• Chromospheric Rapid Blueshifted Excursions Observed with IBIS and Their Association with Photospheric Magnetic Field Evolution

Cited by in corpus (7)

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• Possible Production of Solar Spicules by Microfilament Eruptions
• Oscillatory reconnection as a plasma diagnostic in the solar corona
• Ubiquitous hundred-Gauss magnetic fields in solar spicules
• Searching for signatures of H $\alpha$ spicule-like features in the solar transition region
• The independence of oscillatory reconnection periodicity from the initial pulse