Dynamic Fibrils Are Driven by Magnetoacoustic Shocks

By V. Hansteen, Bart De Pontieu, L. R. V. Voort, M. Noort, M. Carlsson. 2006

248 citations recorded by the source corpus.

The formation of jets such as dynamic fibrils, mottles, and spicules in the solar chromosphere is one of the most important, but also most poorly understood, phenomena of the Sun's magnetized outer atmosphere. We use extremely high resolution observations from the Swedish 1 m Solar Telescope combined with advanced numerical modeling to show that in active regions these jets are a natural consequence of upwardly propagating slow-mode magnetoacoustic shocks. These shocks form when waves generated by convective flows and global p-mode oscillations in the lower lying photosphere leak upward into the magnetized chromosphere. We find excellent agreement between observed and simulated jet velocities, decelerations, lifetimes, and lengths. Our findings suggest that previous observations of quiet-Sun spicules and mottles may also be interpreted in light of a shock-driven mechanism.

Subfields: Astronomy and Astrophysics, Molecular Biology

View Paper: https://www.semanticscholar.org/paper/a17445eafe805752f146ef6f97ad0baaec0b156c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Leenaarts
2. M. Carlsson
3. R. Erdélyi
4. S. Solanki
5. T. Wiegelmann
6. C. Schrijver
7. B. de Pontieu
8. J. Thalmann

In Molecular Biology

1. T. Wiegelmann
2. C. Schrijver
3. J. Thalmann
4. J. Leenaarts
5. S. Solanki
6. A. Title
7. T. Tarbell
8. M. Carlsson

Citations in the corpus

• A Tale of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere (2007, background): “…show that the mechanism that drives type I spicules does not produce jets with (real or apparent) speeds above 50 km/s or rapid fading caused by heating to TR temperatures such as we seem to observe in the type II spicules (Hansteen et al., 2006; De Pontieu et al., 2007; Langangen et al., 2007).”
• The Interface Region Imaging Spectrograph (IRIS) (2012, background): “The propagation of these sound waves along magneticfield lines leads to the formation of slow-mode magneto-acoustic shocks that propel plasma upwards to form so-called dynamic fibrils (Hansteen et al., 2006; De Pontieu et al., 2007b; Rouppe van der Voort et al., 2007; Kato et al., 2011).”
• The magnetic field in the solar atmosphere (2014, background): “But there is also mounting evidence of MHD waves in the chromospheric layers of magnetic structures (Hansteen et al. 2006; De Pontieu et al. 2007).”
• Non-equilibrium hydrogen ionization in 2D simulations of the solar atmosphere (2007, methodology): “We have performed a two-dimensional simulation including non-equilibrium hydrogen ionization in a setup similar to the one used by Hansteen et al. (2006) and De Pontieu et al. (2007).”
• THE FORMATION OF THE Hα LINE IN THE SOLAR CHROMOSPHERE (2012, methodology): “…2004; Hansteen et al. 2007; Gudiksen et al. 2011) These models have been used to study various chromospheric phenomena, such as dynamic fibrils (Hansteen et al. 2006; De Pontieu et al. 2007a), the presence of Alfvénic waves (De Pontieu et al. 2007b), magnetic flux emergence (Mart́ınez-Sykora…”
• OBSERVING THE ROOTS OF SOLAR CORONAL HEATING—IN THE CHROMOSPHERE (2009, background): “A significant fraction of these are likely caused by magnetoacoustic shocks on magnetic flux concentrations (De Pontieu et al. 2004a; Hansteen et al. 2006; De Pontieu et al. 2007a).”
• Oscillations and Waves in Solar Spicules (2009, background): “…channeling photospheric motion, i.e. the superposition of solar global oscillations and convective turbulence, has opened new avenues in the interpretation of spicule dynamics (see also Hansteen et al. (2006); De Pontieu et al. (2007c); Rouppe van der Voort et al. (2007); Heggland et al. (2007)).”
• The Solar Optical Telescope for the Hinode Mission: An Overview (2007, background): “…important for the quiet sun (Khomenko et al., 2005), for emerging flux (Cheung, Schüssler, and Moreno-Insertis, 2007), for chromospheric waves (Skartlien, Stein, and Nordlund, 2000), and for corona-chromospheric connections (Hansteen et al., 2006; Abbett, 2006; Gudiksen and Nordlund, 2005).”
• ON-DISK COUNTERPARTS OF TYPE II SPICULES IN THE Ca ii 854.2 nm AND Hα LINES (2009, background): “…shocks that can be generated by a variety of processes, such as convective buffeting, granular collapse, dissipation of magnetic energy, and leakage of waves into the chromosphere (e.g., Hansteen et al. 2006; De Pontieu et al. 2007a; Heggland et al. 2007; Martinez-Sykora et al. 2009).”
• Solar Fine-Scale Structures. I. Spicules and Other Small-Scale, Jet-Like Events at the Chromospheric Level: Observations and Physical Parameters (2012, background): “They attributed the difference to the radiative processes involved, since the Doppler velocity originates from a wide range of heights in the atmosphere, in contrast to the proper-motion velocity, which is a very local quantity, because it is measured from the sharply defined bright tops of the DFs.”