A5015351811- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Geomagnetism and Paleomagnetism Studies
- Solar Radiation and Photovoltaics
- Geophysics and Gravity Measurements
- Magnetic confinement fusion research
- Astrophysics and Star Formation Studies
- Atmospheric Ozone and Climate
- Advanced materials and composites
- Adaptive optics and wavefront sensing
- Magnetic properties of thin films
- Metallic Glasses and Amorphous Alloys
- Magnetic Properties and Applications
- Powder Metallurgy Techniques and Materials
- Fluid Dynamics and Turbulent Flows
- Astronomy and Astrophysical Research
- solar cell performance optimization
- Astronomical Observations and Instrumentation
- Advanced Thermodynamics and Statistical Mechanics
- Tropical and Extratropical Cyclones Research
- Electrohydrodynamics and Fluid Dynamics
- Spacecraft and Cryogenic Technologies
- Calibration and Measurement Techniques
Instituto de Astrofísica de Canarias
2015-2024
Universidad de La Laguna
2015-2024
High Altitude Observatory
2023
Main Astronomical Observatory
2008-2017
National Academy of Sciences of Ukraine
2002-2017
Frantsevich Institute for Problems in Materials Science
2007-2013
Consejo Superior de Investigaciones Científicas
2007-2013
Lomonosov Moscow State University
2007-2010
Moscow State University
2009
IAC (United States)
2005-2009
A magnetic field modifies the properties of waves in a complex way. Significant advances have been made recently our understanding physics sunspot with help high-resolution observations, analytical theories, as well numerical simulations. We review current ideas field, providing most coherent picture oscillations by present understanding.
In this paper, we study the heating of magnetized solar chromosphere induced by large fraction neutral atoms present in layer. The presence neutrals, together with decrease height collisional coupling, leads to deviations from classical MHD behavior chromospheric plasma. A relative net motion appears between and ionized components, usually referred as ambipolar diffusion. dissipation currents is enhanced orders magnitude due action diffusion, compared standard ohmic We propose that a...
We derive self-consistent formalism for the description of multi-component partially ionized solar plasma, by means coupled equations charged and neutral components an arbitrary number chemical species, radiation field. All approximations assumptions are carefully considered. Generalized Ohm's law is derived single-fluid two-fluid formalism. Our approach analytical with some order-of-magnitude support calculations. After general developed we particularize to frequently considered cases as...
The Daniel K. Inouye Solar Telescope (DKIST) will revolutionize our ability to measure, understand and model the basic physical processes that control structure dynamics of Sun its atmosphere. first-light DKIST images, released publicly on 29 January 2020, only hint at extraordinary capabilities which accompany full commissioning five facility instruments. With this Critical Science Plan (CSP) we attempt anticipate some what those enable, providing a snapshot scientific pursuits hopes engage...
The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of solar atmosphere, from deep photosphere to upper chromosphere. Its design combines knowledge and expertise gathered by physics community during construction operation state-of-the-art telescopes operating in visible near-infrared wavelengths: Swedish 1m (SST), German Vacuum Tower (VTT) GREGOR, French T\'elescope H\'eliographique pour l'\'Etude du Magn\'etisme et des Instabilit\'es Solaires...
Abstract Sunspots are intense regions of magnetic flux that rooted deep below the photosphere. It is well established sunspots host magnetohydrodynamic waves, with numerous observations showing a connection to internal acoustic (or p- )modes Sun. The modes fast waves equipartition layer and thought undergo double mode conversion as they propagate upward into atmosphere sunspots, which can generate Alfvénic in upper atmosphere. We employ 2.5D numerical simulations investigate adiabatic wave...
This paper presents the results of an investigation quiet Sun's magnetic field based on high-resolution infrared spectropolarimetric observations obtained with Tenerife Infrared Polarimeter (TIP) at German VTT Observatorio del Teide. We observed two very regions disc centre. The seeing was exceptionally good during both observing runs, being excellent one them. In cases network intentionally avoided to extent possible, focus analysis characteristics weak polarization signals inter-network...
We present numerical simulations of magnetoacoustic wave propagation from the photosphere to low chromosphere in a magnetic sunspot-like structure. A thick flux tube, with dimensions typical small sunspot, is perturbed by vertical or horizontal velocity pulse at photospheric level. The type mode generated depends on ratio between sound speed cS and Alfvén vA, field inclination location driver, shape direction. Mode conversion observed occur region which both characteristic speeds have...
Waves observed in the photosphere and chromosphere of sunspots show complex dynamics spatial patterns. The interpretation high-resolution sunspot wave observations requires modeling three-dimensional (3D) nonlinear propagation mode transformation upper layers realistic spot model atmospheres. Here, we present first results such modeling. We have developed a 3D numerical code specially designed to calculate response magnetic structures equilibrium an arbitrary perturbation. solves MHD...
While sunspots are easily observed at the solar surface, determining their subsurface structure is not trivial. There two main hypotheses for of sunspots: monolithic model and cluster model. Local helioseismology only means by which we can investigate subphotospheric structure. However, as current linear inversion techniques do yet allow to probe internal with sufficient confidence distinguish between monolith models, development physically realistic sunspot models a priority...
Solar chromosphere consists of a partially ionized plasma, which makes modeling the solar particularly challenging numerical task. Here we numerically model chromospheric waves using two-fluid approach with newly developed code. The code solves equations conservation mass, momentum and energy, together induction equation, for case purely hydrogen plasma collisional coupling between charged neutral fluid components. implementation semi-implicit algorithm allows us to overcome stability...
We report two-dimensional MHD simulations which demonstrate that photospheric 5 minute oscillations can leak into the chromosphere inside small-scale vertical magnetic flux tubes. The results of our numerical experiments are compatible with those inferred from simultaneous spectropolarimetric observations photosphere and obtained Tenerife Infrared Polarimeter (TIP) at 10830 Å. conclude efficiency energy exchange by radiation in solar lead to a significant reduction cutoff frequency may allow...
We analyze the propagation of waves in sunspots from photosphere to chromosphere using time series co-spatial Ca ii H intensity spectra (including its line blends) and polarimetric Si i λ10,827 He λ10,830 multiplet. From Doppler shifts these lines we retrieve variation velocity along sight at several heights. Phase are used obtain relation between oscillatory signals. Our analysis reveals standing frequencies lower than 4 mHz a continuous higher frequencies, which steepen into shocks when...
We study the conversion of fast magnetoacoustic waves to Alfvén by means 2.5D numerical simulations in a sunspot-like magnetic configuration. A fast, essentially acoustic, wave given frequency and number is generated below surface propagates upward through Alfvén/acoustic equipartition layer where it splits into upgoing slow (acoustic) (magnetic) waves. The quickly reflects off steep speed gradient, but around above this reflection height partially converts waves, depending on local relative...
In this paper, we show a "proof of concept" the heating mechanism solar chromosphere due to wave dissipation caused by effects partial ionization. Numerical modeling non-linear propagation in magnetic flux tube, embedded atmosphere, is performed solving system single-fluid quasi-MHD equations, which take into account ambipolar term from generalized Ohm's law. It shown that perturbations waves can be effectively dissipated diffusion. The energy input continuous and more efficient than static...
Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers solar atmosphere. However, it is not clear whether these are externally driven or generated in-situ. We address this question by propagating slow magneto-acoustic waves along a coronal fan loop system. In addition to generally observed decreases in oscillation amplitudes with distance, wave also found be...
We present a detailed guide to advanced collisionless fluid models that incorporate kinetic effects into the framework, and are much closer description than traditional magnetohydrodynamics. Such directly applicable modelling turbulent evolution of vast array astrophysical plasmas, such as solar corona wind, interstellar medium, well accretion disks galaxy clusters. The text can be viewed Landau it is divided two parts. Part 1 dedicated obtained by closing hierarchy with simple (non-Landau...
The importance of the chromosphere in mass and energy transport within solar atmosphere is now widely recognised. This review discusses physics magnetohydrodynamic (MHD) waves instabilities large-scale chromospheric structures as well magnetic flux tubes. We highlight a number key observational aspects that have helped our understanding role various dynamic processes wave phenomena, heating scenario also discussed. focuses on invokes basics plasma context this important layer atmosphere....
We report on results of high resolution two fluid non-linear simulations the Rayleigh Taylor Instability (RTI) at interface between a solar prominence and corona. These follow reported earlier by Popescu Braileanu et al. (2021a,b) linear early RTI dynamics in this environment. The use model that includes collisions neutrals charges, including ionization/recombination, energy momentum transfer, frictional heating. High 2.5D magnetized with magnetic field dominantly normal to slightly sheared...
Abstract The Mancha3D code is a versatile tool for numerical simulations of magnetohydrodynamic (MHD) processes in solar/stellar atmospheres. includes nonideal physics derived from plasma partial ionization, realistic equation state and radiative transfer, which allows performing high-quality magnetoconvection, as well idealized particular processes, such wave propagation, instabilities or energetic events. paper summarizes the equations methods used (Multifluid (-purpose -physics...
We explore the effect of magnetic field when using realistic three-dimensional convection experiments to determine solar element abundances. By carrying out magnetoconvection simulations with a radiation-hydro code (the Copenhagen stagger code) and through a-posteriori spectral synthesis three Fe I lines, we obtain evidence that moderate amounts mean flux cause noticeable change in derived equivalent widths compared those for non-magnetic case. The corresponding abundance correction density...