Unveiling the magnetic nature of chromospheric vortices

Murabito, M.; Shetye, Juie; Stangalini, M.; Verwichte, E.; Arber, T. D.; Ermolli, I.; Giorgi, F.; Goffrey, T.

doi:10.1051/0004-6361/202038360

Cited by 18 publications

(14 citation statements)

References 33 publications

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“…In the literature, the terms 'vortex' and 'swirl' are both employed to identify rotating structures in the flows. A large review of the vortex (or swirls) detection is given in Murabito et al (2020). Photospheric vortex flows are usually correlated with a network of magnetic elements at supergranular vertices (Requerey et al 2018).…”

Section: Persistent Downflows In 2 H 30 Min Hinode Observationsmentioning

confidence: 99%

“…Some of the longlasting vortex flows were located at supergranular junction vertices (Attie et al 2009(Attie et al , 2016Requerey et al 2018). The related downflows also represent transient processes for magnetic field intensification associated with the formation of bright points in the continuum (Berger et al 2004;Bello González et al 2009;Narayan 2011).…”

Section: Introductionmentioning

confidence: 98%

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Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation

Roudier

Švanda

Malherbe

et al. 2021

A&A

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Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone, at least in its outer part. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun but also the outer layers. We study the sets of Dopplergrams and magnetograms observed with Solar Dynamics Observatory and Hinode spacecrafts and an magnetohydrodynamic (MHD) simulation. All of the aligned sequences, which were corrected from the satellite motions and tracked with the differential rotation, were used to detect the long-lasting downflows in the quiet-Sun at the disc centre. To learn about the structure of the flows below the solar surface, the time-distance local helioseismology was used. The inspection of the 3D data cube (x, y, t) of the 24 h Doppler sequence allowed us to detect 13 persistent downflows. Their lifetimes lie in the range between 3.5 and 20 h with a sizes between 2″ and 3″ and speeds between −0.25 and −0.72 km s−1. These persistent downflows are always filled with the magnetic field with an amplitude of up to 600 Gauss. The helioseismic inversion allows us to describe the persistent downflows and compare them to the other (non-persistent) downflows in the field of view. The persistent downflows seem to penetrate much deeper and, in the case of a well-formed vortex, the vorticity keeps its integrity to the depth of about 5 Mm. In the MHD simulation, only sub-arcsecond downflows are detected with no evidence of a vortex comparable in size to observations at the surface of the Sun. The long temporal sequences from the space-borne allows us to show the existence of long-persistent downflows together with the magnetic field. They penetrate inside the Sun but are also connected with the anchoring of coronal loops in the photosphere, indicating a link between downflows and the coronal activity. A links suggests that EUV cyclones over the quiet Sun could be an effective way to heat the corona.

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Section: Persistent Downflows In 2 H 30 Min Hinode Observationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation

Roudier

Švanda

Malherbe

et al. 2021

A&A

View full text Add to dashboard Cite

show abstract

Section: Observations and Data Analysismentioning

confidence: 99%

Analysis of Pseudo-Lyapunov Exponents of Solar Convection Using State-of-the-Art Observations

Viavattene

Murabito

Guglielmino

et al. 2021

Entropy

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The solar photosphere and the outer layer of the Sun’s interior are characterized by convective motions, which display a chaotic and turbulent character. In this work, we evaluated the pseudo-Lyapunov exponents of the overshooting convective motions observed on the Sun’s surface by using a method employed in the literature to estimate those exponents, as well as another technique deduced from their definition. We analyzed observations taken with state-of-the-art instruments at ground- and space-based telescopes, and we particularly benefited from the spectro-polarimetric data acquired with the Interferometric Bidimensional Spectrometer, the Crisp Imaging SpectroPolarimeter, and the Helioseismic and Magnetic Imager. Following previous studies in the literature, we computed maps of four quantities which were representative of the physical properties of solar plasma in each observation, and estimated the pseudo-Lyapunov exponents from the residuals between the values of the quantities computed at any point in the map and the mean of values over the whole map. In contrast to previous results reported in the literature, we found that the computed exponents hold negative values, which are typical of a dissipative regime, for all the quantities derived from our observations. The values of the estimated exponents increase with the spatial resolution of the data and are almost unaffected by small concentrations of magnetic field. Finally, we showed that similar results were also achieved by estimating the exponents from residuals between the values at each point in maps derived from observations taken at different times. The latter estimation technique better accounts for the definition of these exponents than the method employed in previous studies.

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“…The data set was calibrated using the IBIS standard calibration pipeline (e.g., [64,65]), and was further processed with a post facto restoring technique, the multi-object multi-frame blind deconvolution (MOMFBD, [66]), which removes for a large part any residual distortions left by AO systems. More details about this data set can be found in Murabito et al [67]. Moreover, we analyzed observations acquired on 25 May 2017 with the Crisp Imaging SpectroPolarimeter (CRISP, [68]) installed at the Swedish 1 m solar telescope (SST), located in Roque de los Muchachos Observatory, La Palma, Canary Islands (Spain).…”

Section: Observations and Data Analysis 21 Observationsmentioning

confidence: 99%

Analysis of Pseudo-Lyapunov Exponents of Solar Convection Using State-of-the-Art Observations

Viavattene,

Murabito,

Guglielmino

et al. 2021

Preprint

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Unveiling the magnetic nature of chromospheric vortices

Cited by 18 publications

References 33 publications

Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation

Photospheric downflows observed with SDO/HMI, HINODE, and an MHD simulation

Analysis of Pseudo-Lyapunov Exponents of Solar Convection Using State-of-the-Art Observations

Analysis of Pseudo-Lyapunov Exponents of Solar Convection Using State-of-the-Art Observations

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