The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter

Kahil, F.; Hirzberger, J.; Solanki, S. K.; Chitta, L. P.; Peter, Hardi; Auchère, F.; Sinjan, Jonas; Suárez, D. Orozco; Albert, K.; Jorge, N. Albelo; Appourchaux, T.; Álvarez-Herrero, Alberto; Rodríguez, J. Blanco; Gandorfer, A.; Germerott, D.; Guerrero, Lucas; Márquez, P. Gutiérrez; Kolleck, M.; Iniesta, J. C. del Toro; Volkmer, R.; Woch, J.; Fiethe, Björn; Cama, Jehangir; Pérez-Grande, Isabel; Sanchis-Kilders, E.; Jiménez, M. Balaguer; Rubio, L. R. Bellot; Calchetti, D.; Carmona, Mamen; Deutsch, W.; Fernández-Rico, Germán; Fernández-Medina, Ana; Parejo, Pilar García; Gasent-Blesa, J. L.; Gizon, Laurent; Grauf, B.; Heerlein, K.; Lagg, A.; Lange, Tobias; Jiménez, Antonio López; Maue, T.; Meller, R.; Michalik, H.; Vacas, A. Moreno; Müller, Roland; Nakai, E.; Schmidt, Wolfgang; Schou, J.; Schühle, U.; Staub, Jan; Strecker, Hanna; Torralbo, Ignacio; Valori, G.; Cuadrado, R. Aznar; Teriaca, L.; Berghmans, David; Kraaikamp, E.; Gissot, S.

doi:10.1051/0004-6361/202142873

Cited by 18 publications

(5 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later Kahil et al (2022) also examined the line-of-sight photospheric magnetic field evolution of campfires using Solar Orbiter's PHI data and found similar results to Panesar et al (2021), in that majority of campfires are triggered by magnetic flux cancelation. Some of the campfires show similarities with coronal jets (e.g., Panesar et al 2016bPanesar et al , 2018aHou et al 2021;Panesar et al 2021).…”

Section: Introductionmentioning

confidence: 74%

Solar Orbiter and SDO Observations, and a Bifrost Magnetohydrodynamic Simulation of Small-scale Coronal Jets

Panesar

Hansteen

Tiwari

et al. 2023

ApJ

View full text Add to dashboard Cite

We report high-resolution, high-cadence observations of five small-scale coronal jets in an on-disk quiet Sun region observed with Solar Orbiter’s EUI/HRIEUV in 174 Å. We combine the HRIEUV images with the EUV images of SDO/AIA and investigate the magnetic setting of the jets using coaligned line-of-sight magnetograms from SDO/HMI. The HRIEUV jets are miniature versions of typical coronal jets as they show narrow collimated spires with a base brightening. Three out of five jets result from a detectable minifilament eruption following flux cancelation at the neutral line under the minifilament, analogous to coronal jets. To better understand the physics of jets, we also analyze five small-scale jets from a high-resolution Bifrost MHD simulation in synthetic Fe ix/Fe x emissions. The jets in the simulation reside above neutral lines and four out of five jets are triggered by magnetic flux cancelation. The temperature maps show evidence of cool gas in the same four jets. Our simulation also shows the signatures of opposite Doppler shifts (of the order of ±10 s of km s−1) in the jet spire, which is evidence of untwisting motion of the magnetic field in the jet spire. The average jet duration, spire length, base width, and speed in our observations (and in synthetic Fe ix/Fe x images) are 6.5 ± 4.0 min (9.0 ± 4.0 minutes), 6050 ± 2900 km (6500 ± 6500 km), 2200 ± 850 km, (3900 ± 2100 km), and 60 ± 8 km s−1 (42 ± 20 km s−1), respectively. Our observation and simulation results provide a unified picture of small-scale solar coronal jets driven by magnetic reconnection accompanying flux cancelation. This picture also aligns well with the most recent reports of the formation and eruption mechanisms of larger coronal jets.

show abstract

Section: Introductionmentioning

confidence: 74%

Solar Orbiter and SDO Observations, and a Bifrost Magnetohydrodynamic Simulation of Small-scale Coronal Jets

Panesar

Hansteen

Tiwari

et al. 2023

ApJ

View full text Add to dashboard Cite

show abstract

“…The “X” indicates the location of one of the detected simulated brightenings, which occurs between opposite-polarity magnetic-field patches (indicated with red and blue contours). EUV brightenings are usually observed to occur between opposite magnetic-field polarities (e.g., Zhukov et al., 2021 ; Kahil et al., 2022 ). While it is beyond the scope of the current study to investigate the relationship between individual simulated brightenings and the magnetic-field configuration, this will be considered in the future, when high-resolution SO/PHI observations are available to drive the simulation at the same time and with the same cadence as the EUI observations.…”

Section: Simulationmentioning

confidence: 99%

“…Previous EUI observations have shown that the EUV brightenings are located between 1000 km and 5000 km above the photosphere (Zhukov et al., 2021 ). Most EUV brightenings appear to be located at the neutral line between patches of two opposite magnetic-field polarities (Panesar et al., 2021 ; Kahil et al., 2022 ), indicating the importance of the magnetic field in the formation and evolution of these features.…”

Section: Introductionmentioning

confidence: 99%

A Statistical Comparison of EUV Brightenings Observed by SO/EUI with Simulated Brightenings in Nonpotential Simulations

et al. 2022

View full text Add to dashboard Cite

The High Resolution Imager (HRIEUV) telescope of the Extreme Ultraviolet Imager (EUI) instrument onboard Solar Orbiter has observed EUV brightenings, so-called campfires, as fine-scale structures at coronal temperatures. The goal of this paper is to compare the basic geometrical (size, orientation) and physical (intensity, lifetime) properties of the EUV brightenings with regions of energy dissipation in a nonpotential coronal magnetic-field simulation. In the simulation, HMI line-of-sight magnetograms are used as input to drive the evolution of solar coronal magnetic fields and energy dissipation. We applied an automatic EUV-brightening detection method to EUV images obtained on 30 May 2020 by the HRIEUV telescope. We applied the same detection method to the simulated energy dissipation maps from the nonpotential simulation to detect simulated brightenings. We detected EUV brightenings with a density of $1.41 \times 10^{-3}$ 1.41 × 10 − 3 brightenings/Mm2 in the EUI observations and simulated brightenings between $2.76\times 10^{-2}$ 2.76 × 10 − 2 – $4.14\times 10^{-2}$ 4.14 × 10 − 2 brightenings/Mm2 in the simulation, for the same time range. Although significantly more brightenings were produced in the simulations, the results show similar distributions of the key geometrical and physical properties of the observed and simulated brightenings. We conclude that the nonpotential simulation can successfully reproduce statistically the characteristic properties of the EUV brightenings (typically with more than 85% similarity); only the duration of the events is significantly different between observations and simulation. Further investigations based on high-cadence and high-resolution magnetograms from Solar Orbiter are under consideration to improve the agreement between observation and simulation.

show abstract

“…Furthermore, flux cancellation in regions of complex mixed polarity has been observed in association with brightenings in the cores of active regions (Chitta et al 2018(Chitta et al , 2020. Also, evidence has been presented that most of the small-scale campfires are formed by magnetic reconnection driven by flux cancellation (Panesar et al 2021), which occurs either between two main footpoints of a bipolar feature or between one of those footpoints and a nearby magnetic fragment of opposite polarity (Kahil et al 2022).…”

Section: Introductionmentioning

confidence: 96%

Coronal Heating and Solar Wind Generation by Flux Cancellation Reconnection

Pontin,

Priest,

Chitta

et al. 2023

ApJ

Self Cite

View full text Add to dashboard Cite

In this paper, we propose that flux cancellation on small granular scales (≲1000 km) ubiquitously drives reconnection at a multitude of sites in the low solar atmosphere, contributing to chromospheric/coronal heating and the generation of the solar wind. We analyze the energy conversion in these small-scale flux cancellation events using both analytical models and three-dimensional, resistive magnetohydrodynamic (MHD) simulations. The analytical models—in combination with the latest estimates of flux cancellation rates—allow us to estimate the energy release rates due to cancellation events, which are found to be on the order 106–107 erg cm−2 s−1, sufficient to heat the chromosphere and corona of the quiet Sun and active regions, and to power the solar wind. The MHD simulations confirm the conversion of energy in reconnecting current sheets, in a geometry representing a small-scale bipole being advected toward an intergranular lane. A ribbon-like jet of heated plasma that is accelerated upward could also escape the Sun as the solar wind in an open-field configuration. We conclude that through two phases of atmospheric energy release—precancellation and cancellation—the cancellation of photospheric magnetic flux fragments and the associated magnetic reconnection may provide a substantial energy and mass flux contribution to coronal heating and solar wind generation.

show abstract

The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter

Cited by 18 publications

References 58 publications

Solar Orbiter and SDO Observations, and a Bifrost Magnetohydrodynamic Simulation of Small-scale Coronal Jets

Solar Orbiter and SDO Observations, and a Bifrost Magnetohydrodynamic Simulation of Small-scale Coronal Jets

A Statistical Comparison of EUV Brightenings Observed by SO/EUI with Simulated Brightenings in Nonpotential Simulations

Coronal Heating and Solar Wind Generation by Flux Cancellation Reconnection

Contact Info

Product

Resources

About