Short dynamic fibrils in sunspot chromospheres

Abstract

Sunspot chromospheres display vigorous oscillatory signature when observed in chromospheric diagnostics like the strong Ca II lines and H-alpha. New high-resolution sunspot observations from the Swedish 1-m Solar Telescope show the ubiquitous presence of small-scale periodic jet-like features that move up and down. This phenomenon has not been described before. Their typical width is about 0.3 arcsec and they display clear parabolic trajectories in space-time diagrams. The maximum extension of the top of the jets is lowest in the umbra, a few 100 km, and progressively longer further away from the umbra in the penumbra, with the longest more than 1000 km. These jets resemble dynamic fibrils found in plage regions but at smaller extensions. LTE inversion of spectro-polarimetric Ca II 8542 observations enabled for a comparison of the magnetic field inclination and the properties of these short jets. We find that the most extended of these jets also have longer periods and tend to be located in regions with more horizontal magnetic fields. This is a direct observational confirmation of the mechanism of long-period waves propagating along inclined magnetic fields into the solar chromosphere. This mechanism was identified earlier as the driver of dynamic fibrils in plage, part of the mottles in quiet Sun, and type I spicules at the limb. The sunspot dynamic fibrils that we report here represent a new class of manifestation of this mechanism. They are not the same as the transient penumbral and umbral micro-jets reported earlier.

animations of figures can be found at http://folk.uio.no/rouppe/dfsunspot/

References in corpus (14)

• CRISP Spectropolarimetric Imaging of Penumbral Fine Structure
• Dynamic Fibrils are driven by Magnetoacoustic Shocks
• High Resolution Observations and Modeling of Dynamic Fibrils
• Magneto-convection in a sunspot umbra
• MHD simulations of penumbra fine structure
• Physical Properties of a Sunspot Chromosphere with Umbral Flashes
• Magnetoacoustic shocks as driver of quiet Sun mottles
• 3D Temperature Mapping of Solar Photospheric Fine Structure Using Ca II H Filtergrams
• Stokes imaging polarimetry using image restoration at the Swedish 1-m Solar Telescope
• Opposite polarity field with convective downflow and its relation to magnetic spines in a sunspot penumbra
• Heating of the magnetic chromosphere: observational constraints from Ca II 8542 spectra
• Spectroscopic measurements of dynamic fibrils in the Ca {\small{II}} 8662 Å line
• Measurements of plasma motions in dynamic fibrils
• Fine structures in the atmosphere above a sunspot umbra

Cited by in corpus (36)

• CRISPRED: A data pipeline for the CRISP imaging spectropolarimeter
• Solar science with the Atacama Large Millimeter/submillimeter Array - A new view of our Sun
• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
• The European Solar Telescope
• Frequently Occurring Reconnection Jets from Sunspot Light Bridges
• On fibrils and field lines: The nature of H$\alpha$ fibrils in the solar chromosphere
• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• Fan-shaped jets above the light bridge of a sunspot driven by reconnection
• Inference of the chromospheric magnetic field orientation in the Ca II 8542 A line fibrils
• Slender Ca II H Fibrils Mapping Magnetic Fields in the Low Solar Chromosphere
• Surge-like oscillations above sunspot light bridges driven by magnetoacoustic shocks
• On the Active Region Bright Grains Observed in the Transition Region Imaging Channels of IRIS
• Temperature constraints from inversions of synthetic solar optical, UV and radio spectra
• A Hot Downflowing Model Atmosphere For Umbral Flashes And The Physical Properties Of Their Dark Fibrils
• High Resolution Observations of Chromospheric Jets in Sunspot Umbra
• H-alpha features with hot onsets III. Fibrils in Lyman-alpha and with ALMA
• Observationally based models of penumbral microjets
• Chromospheric polarimetry through multi-line observations of the 850 nm spectral region
• Dynamics in Sunspot Umbra as Seen in New Solar Telescope and Interface Region Imaging Spectrograph Data
• Umbral chromospheric fine structure and umbral flashes modelled as one: the corrugated umbra
• The formation of small-scale umbral brightenings in sunspot atmospheres
• The Propagation of Coherent Waves Across Multiple Solar Magnetic Pores
• Stable Umbral Chromospheric Structures
• Multi-wavelength Study of Transition Region Penumbral Subarcsecond Bright Dots Using IRIS and NST
• Signatures of dynamic fibrils at the coronal base: Observations from Solar Orbiter/EUI
• Evolution Of Super-Sonic Downflows In A Sunspot
• H-alpha features with hot onsets. II. A contrail fibril
• Downflowing umbral flashes as an evidence of standing waves in sunspot umbrae
• Sunspot penumbral filaments intruding into a light bridge and the resultant reconnection jets
• First Observation of Chromospheric Waves in a Sunspot by DKIST/ViSP: The Anatomy of an Umbral Flash
• The formation and heating of chromospheric fibrils in a radiation-MHD simulation
• The dynamics of 3-minute wavefronts and their relation to sunspot magnetic fields
• The dark side of penumbral microjets: Observations in Hα
• Evolution Of Downflows In The Transition Region Above A Sunspot Over Short Time-Scales
• Impact of opacity effects on chromospheric oscillations inferred from NLTE inversions
• The group height of spicules links their acceleration and velocity