On the linear structure of the interlaced Alfvén vortices in the tail of Uranus at solstice. DOI Creative Commons
F. Pantellini

Research Square (Research Square), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 1, 2023

Abstract Incompressible vortex flow are observed in a large variety of astrophysical plasmas such as the convection zone and atmosphere stars, jets stellar winds planetary magnetospheres. More specifically, magnetohydrodynamic (MHD) simulations have shown that two scale interlaced Alfvénic vortices structure magnetic tail Uranus at solstice time. Assuming identical vortices, we compute general linear near their centers within frame ideal MHD. We then use analytic results to interpret qualify 3D MHD simulation fast rotating Uranus-type planet.

Language: Английский

Seven decades of exploring planetary interiors with rotating convection experiments DOI Creative Commons
Alban Pothérat, Susanne Horn

Comptes Rendus Physique, Journal Year: 2025, Volume and Issue: 25(S3), P. 1 - 55

Published: Feb. 25, 2025

Language: Английский

Citations

1
Magnetohydrodynamic Poynting Flux Vortices in the Solar Atmosphere and Their Role in Concentrating Energy DOI Creative Commons
Suzana S. A. Silva, G. Verth, Erico L. Rempel

et al.

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 963(1), P. 10 - 10

Published: Feb. 21, 2024

Abstract The nature of energy generation, transport, and effective dissipation responsible for maintaining a hot solar upper atmosphere is still elusive. Poynting flux vital parameter describing the direction magnitude flow, which mainly used in physics estimating upward generated by photospheric plasma motion. This study presents pioneering 3D mapping magnetic transport within numerically simulated atmosphere. By calculating Finite Time Lyapunov Exponent velocity, defined as ratio to density, we precisely identify sources destinations flow throughout reveals presence barriers lower atmosphere, restricting amount from photosphere reaching chromosphere corona. Interacting kinematic vortices create channels, breaking through these allowing three times more input motions reach than before formed. vortex system also substantially alters mapping, acting source deposition energy, leading localized concentration. Furthermore, our results show that transported following vortical motion: vortex. In regions where coexist, they favor conditions ohmic viscous heating, since naturally large gradients velocity fields over small spatial scales. Hence, promotes local temperatures around million Kelvins.

Language: Английский

Citations

6
Can the Solar p-modes Contribute to the High-frequency Transverse Oscillations of Spicules? DOI Creative Commons
Hidetaka Kuniyoshi, Munehito Shoda, R. J. Morton

et al.

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 960(2), P. 118 - 118

Published: Jan. 1, 2024

Abstract Lateral motions of spicules serve as vital indicators transverse waves in the solar atmosphere, and their study is crucial for understanding wave-heating process corona. Recent observations have focused on high-frequency (periods < 100 s), which potential to transport sufficient energy coronal heating. These spicule oscillations are distinct from granular motions, much longer timescales 5–10 minutes. Instead, it proposed that they generated through mode conversion longitudinal arise a shock-steepening process. Therefore, these may not solely be produced by horizontal buffeting granulation but also leakage p -mode oscillations. To investigate contribution -modes, our employs two-dimensional magneto-convection simulation spanning upper convection zone During course simulation, we introduce -mode-like driver at bottom boundary. We reveal notable increase mean velocity amplitude spicules, ranging 10%–30%, attribute this transfer waves. This effect results an enhancement estimated flux 30%–80%.

Language: Английский

Citations

4
Effect of Magnetic Diffusion in the Chromosphere on the Solar Wind DOI Creative Commons
Masato Matsuoka, Takeru K. Suzuki, Takato Tokuno

et al.

The Astrophysical Journal, Journal Year: 2024, Volume and Issue: 970(1), P. 16 - 16

Published: July 1, 2024

Abstract We investigate nonideal magnetohydrodynamical (MHD) effects in the chromosphere on solar wind by performing MHD simulations for Alfvén-wave-driven winds, explicitly including ohmic and ambipolar diffusion. find that waves are significantly damped diffusion so Alfvénic Poynting flux reaches corona is substantially reduced. As a result, coronal temperature mass-loss rate of considerably reduced, compared with those obtained from an ideal case, which indicative great importance atmosphere. However, recovered small increase convection-originated velocity perturbation at photosphere because sensitive dependence reflection Alfvén physical properties chromosphere. also density perturbations reduced nonlinear generation compressible suppressed.

Language: Английский

Citations

4
How numerical treatments of the transition region modify energy flux into the solar corona DOI Creative Commons
T. A. Howson, C. Breu

Monthly Notices of the Royal Astronomical Society, Journal Year: 2023, Volume and Issue: 526(1), P. 499 - 511

Published: Sept. 14, 2023

ABSTRACT The large temperature gradients in the solar transition region present a significant challenge to large-scale numerical modelling of Sun’s atmosphere. In response, variety techniques have been developed which modify thermodynamics system. This sacrifices accuracy favour accurately tracking coronal response heating events. Invariably, modification leads an artificial broadening region. Meanwhile, many contemporary models atmosphere rely on energy flux from lower atmosphere, through and into corona. this paper, we quantify how thermodynamic modifications affect rate injection We consider series one-dimensional atmospheric loops with different resolutions treatments thermodynamics. Then, using Alfvén waves as proxy, rates are modified each case. find that treatment resolution significantly traveltimes, eigenfrequencies eigenmodes system, at is injected Alarmingly, frequency dependent, meaning it may be difficult compare effects velocity drivers if they imposed below under-resolved region, even sophisticated adaptations implemented.

Language: Английский

Citations

8
Swirls in the solar corona DOI Creative Commons
C. Breu, Hardi Peter,

R. Cameron

et al.

Astronomy and Astrophysics, Journal Year: 2023, Volume and Issue: 675, P. A94 - A94

Published: May 17, 2023

Vortex flows have been found in the photosphere, chromosphere and low corona observations simulations. It has suggested that vortices play an important role for channeling energy plasma into corona, but impact of vortex on not directly studied a realistic setup. We investigate coronal heating using high resolution simulations loops. The are artificially driven, arise self-consistently from magnetoconvection. perform 3D resistive MHD with MURaM code. Studying isolated loop Cartesian geometry allows us to resolve structure interior. conduct statistical analysis determine properties as function height corona. find injected is generated by internal coherent motions within strong magnetic elements. A significant part resulting Poynting flux channeled through tubes forming connection between photosphere Vortices can form contiguous structures reach up heights, itself get deformed eventually lose their identity increasing height. show increased upward directed rate both effect becomes less pronounced While transport structuring importance higher atmosphere clear since swirls distinguishable environment. reaching complex relationship emission.

Language: Английский

Citations

5
Formulating Mass-loss Rates for Sun-like Stars: A Hybrid Model Approach DOI Creative Commons
Munehito Shoda, Steven R. Cranmer, Shin Toriumi

et al.

The Astrophysical Journal, Journal Year: 2023, Volume and Issue: 957(2), P. 71 - 71

Published: Oct. 31, 2023

Abstract We observe an enhanced stellar wind mass-loss rate from low-mass stars exhibiting higher X-ray flux. This trend, however, does not align with the Sun, where no evident correlation between flux and is present. To reconcile these observations, we propose a hybrid model for solar-type stars, incorporating both Alfvén wave dynamics emergence-driven interchange reconnection, increasingly studied concept guided by latest heliospheric observations. For establishing scaling law, perform series of magnetohydrodynamic simulations across varied magnetic activities. Through parameter survey concerning surface (unsigned) (Φ surf ) open-to-surface ratio ( ξ open = Φ /Φ ), derive law given M ̇ w / , ⊙ = Φ surf 0.52 ξ open 0.86 , ${\dot{M}}_{w,\odot }=2.0\times {10}^{-14}\ {M}_{\odot }\ {\mathrm{yr}}^{-1}$?> 2.0 × 10 − 14 width="0.33em" yr 1 ${{\rm{\Phi }^{\mathrm{surf}}=3.0\times {10}^{23}\ \mathrm{Mx}$?> 3.0 23 Mx ${\xi }^{\mathrm{open}}=0.2$?> 0.2 . By comparing cases without emergence, find that increase in can be attributed to influence emergence. Our demonstrates agreement solar observations spanning 40 yr, superior performance when compared X-ray-based estimations. findings suggest emergence may play significant role winds particularly those originating magnetically active stars.

Language: Английский

Citations

5
Periodic Coronal Rain Driven by Self-consistent Heating Process in a Radiative Magnetohydrodynamic Simulation DOI Creative Commons
Zekun Lu, Feng Chen, Jinhan Guo

et al.

The Astrophysical Journal Letters, Journal Year: 2024, Volume and Issue: 973(1), P. L1 - L1

Published: Sept. 1, 2024

Abstract The periodic coronal rain and in-phase radiative intensity pulsations have been observed in multiple wavelengths recent years. However, due to the lack of three-dimensional magnetic fields thermodynamic data observations, it remains challenging quantify heating rate that drives mass cycles. In this work, based on MURaM code, we conduct a magnetohydrodynamic simulation spanning from convective zone corona, where solar atmosphere is heated self-consistently through dissipation resulting magnetoconvection. For first time, model an active region. With high spatial resolution, well resembles observational features across different extreme-ultraviolet wavelengths. These include realistic interweaving loops, rain, pulsations, with two periods 3.0 hr 3.7 identified within one loop system. Moreover, allows for detailed depiction small scales, revealing adjacent shower-like clumps ∼500 km width showcasing their multithermal internal structures. We further reveal these variations essentially reflect cyclic energy evolution under thermal nonequilibrium state. Importantly, as driver circulation, self-consistent considerably complex time space, hour-level 1 order magnitude, minute-level bursts, varying asymmetry reaching ten times between footpoints. This provides instructive template ad hoc function enhances our understanding process.

Language: Английский

Citations

1
MUSE observations of small-scale heating events DOI Creative Commons
C. Breu, I. De Moortel, Paola Testa

et al.

Monthly Notices of the Royal Astronomical Society, Journal Year: 2024, Volume and Issue: 531(1), P. 1671 - 1684

Published: April 27, 2024

ABSTRACT Constraining the processes that drive coronal heating from observations is a difficult task due to complexity of solar atmosphere. As upcoming missions such as Multi-slit Solar Explorer (MUSE) will provide with unprecedented spatial and temporal resolution, numerical simulations are becoming increasingly realistic. Despite availability synthetic models, line-of-sight effects magnetic topology in realistic set-up still complicate prediction signatures for specific processes. 3D magnetohydrodynamic (MHD) have shown significant part Poynting flux injected into atmosphere carried by small-scale motions, vortices driven rotational flows inside intergranular lanes. MHD waves excited these been suggested play an important role energy transfer between different atmospheric layers. Using spectroscopic data generated loop model incorporating driving magnetoconvection, we study whether transport eventual dissipation can be identified future MUSE.

Language: Английский

Citations

0
On the linear structure of the interlaced Alfvén vortices in the tail of Uranus at solstice DOI
F. Pantellini

Astrophysics and Space Science, Journal Year: 2024, Volume and Issue: 369(6)

Published: June 1, 2024

Language: Английский

Citations

0