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相关论文: On the power spectrum of solar surface flows

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Context: Supergranulation is a pattern of the velocity field at the surface of the Sun, which has been known about for more than fifty years, however, no satisfactory explanation of its origin has been proposed. Aims: New observational…

We model the solar horizontal velocity power spectrum at scales larger than granulation using a two-component approximation to the mass continuity equation. The model takes four times the density scale height as the integral (driving) scale…

太阳与恒星天体物理 · 物理学 2015-06-22 J. W. Lord , R. H. Cameron , M. P. Rast , M. Rempel , T. Roudier

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different…

太阳与恒星天体物理 · 物理学 2015-10-01 David H. Hathaway , Thibaud Teil , Aimee A. Norton , Irina Kitiashvili

Aims: The interactions of velocity scales on the Sun's surface, from granulation to supergranulation are still not understood, nor are their interaction with magnetic fields. We thus aim at giving a better description of dynamics in the…

太阳与恒星天体物理 · 物理学 2009-02-16 T. Roudier , M. Rieutord , D. Brito , F. Rincon , J. M. Malherbe , N. Meunier , T. Berger , Z. Frank

This study used Speckle Visibility Spectroscopy to examine velocity fluctuations in a three-dimensional granular heap flow, where the mean velocity profile consists of a fast-flow surface layer and a creep layer beneath. The velocity…

软凝聚态物质 · 物理学 2025-03-18 ShuChang Yu , Jin Shang , YangRui Chen , Ran Li , Quan Chen , Hui Yang , Hu Zheng , Jie Zhang

In the quiet regions on the solar surface, turbulent convective motions of granulation play an important role in creating small-scale magnetic structures, as well as in energy injection into the upper atmosphere. The turbulent nature of…

太阳与恒星天体物理 · 物理学 2020-03-04 Ryohtaroh T. Ishikawa , Yukio Katsukawa , Takayoshi Oba , Motoki Nakata , Kenichi Nagaoka , Tatsuya Kobayashi

We analyze spectral properties of solar convection in the range of depths from 0 to 19~Mm using subsurface flow maps obtained by the time-distance heiioseismology analysis of solar-oscillation data from the Helioseismic and Magnetic Imager…

太阳与恒星天体物理 · 物理学 2022-03-01 Alexander V. Getling , Alexander G. Kosovichev

Below the scale of supergranules we find that cellular flows are present in the solar photosphere at two distinct size scales, approximately 2 Mm and 4 Mm, with distinct characteristic times. Simultaneously present in the flow is a…

天体物理学 · 物理学 2015-06-24 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin

Hydrodynamic simulations of granular convection predict the existence of supersonic flows covering ~3-4% of the solar surface at any time, but these flows have not been detected unambigously as yet. Using data from the spectropolarimeter…

太阳与恒星天体物理 · 物理学 2009-07-22 L. R. Bellot Rubio

Gas convection is observed in the solar photosphere as the granulation, i.e., having highly time-dependent cellular patterns, consisting of numerous bright cells called granules and dark surrounding-channels called intergranular lanes. Many…

太阳与恒星天体物理 · 物理学 2020-03-04 T. Oba , Y. Iida , T. Shimizu

Results of realistic simulations of solar surface convection on the scale of supergranules (96 Mm wide by 20 Mm deep) are presented. The simulations cover only 10% of the geometric depth of the solar convection zone, but half its pressure…

天体物理学 · 物理学 2008-11-05 R. F. Stein , A. Nordlund , D. Georgobiani , D. Benson , W. Schaffenberger

We use subsurface-flow velocity maps inferred by time--distance helioseismology from Doppler measurements with the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory (SDO) to investigate variations of large-scale…

太阳与恒星天体物理 · 物理学 2025-10-01 Alexander V. Getling , Alexander G. Kosovichev

Supergranulation is characterized by horizontally divergent flows with typical length scales of 32 Mm in the solar photosphere. Unlike granulation, the size of which is comparable to both the thickness of the radiative boundary layer and…

太阳与恒星天体物理 · 物理学 2016-10-05 Jean-Francois Cossette , Mark Peter Rast

We have performed power spectral analysis of surface temperatures, velocities, and magnetic fields, using spectro-polarimetric data taken with the Hinode Solar Optical Telescope. When we make power spectra in a field-of-view covering the…

太阳与恒星天体物理 · 物理学 2015-06-11 Y. Katsukawa , D. Orozco Suarez

In the recent papers, we introduced a method utilised to measure the flow field. The method is based on the tracking of supergranular structures. We did not precisely know, whether its results represent the flow field in the photosphere or…

天体物理学 · 物理学 2012-08-27 Michal Svanda , Mirek Klvana , Michal Sobotka , Alexander G. Kosovichev , Tom L. Duvall,

The solar photosphere provides us with a laboratory for understanding turbulence in a layer where the fundamental processes of transport vary rapidly and a strongly superadiabatic region lies very closely to a subadiabatic layer. Our tools…

We apply time-distance helioseismology, local correlation tracking and Fourier spatial-temporal filtering methods to realistic supergranule scale simulations of solar convection and compare the results with high-resolution observations from…

We employ time sequences of images observed with a G-band filter (4305{\AA}) by the Solar Optical Telescope (SOT) on board of Hinode spacecraft at different latitude along solar central me-ridian to study vorticity of granular flows in…

太阳与恒星天体物理 · 物理学 2017-02-02 A. A. Pevtsov

We present the results of a statistical analysis of the Doppler shifts and the asymmetry parameters of V profiles of the Fe I 630.25 nm line produced by 2D MHD simulations of solar granulation. The realism of the simulations tested using…

太阳与恒星天体物理 · 物理学 2010-07-21 V. A. Sheminova

The solar photosphere is the visible surface of the Sun, where many bright granules, surrounded by narrow dark intergranular lanes, are observed everywhere. The granular pattern is a manifestation of convective motion at the photospheric…

太阳与恒星天体物理 · 物理学 2017-02-15 T. Oba , Y. Iida , T. Shimizu
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