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相关论文: Temporal variations in the acoustic signal from fa…

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Analysis of over 36 years of time series data from the NSO/AFRL/Sac Peak K-line monitoring program elucidates five components of the variation of the seven measured chromospheric parameters: (a) the solar cycle (period ~ 11 years), (b)…

太阳与恒星天体物理 · 物理学 2015-06-15 Jeffrey Scargle , Stephen Keil , Pete Worden

Detection of solar gravity modes remains a major challenge to our understanding of the innerparts of the Sun. Their frequencies would enable the derivation of constraints on the core physical properties while their amplitudes can put severe…

天体物理学 · 物理学 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

Planetary-scale waves at the Venusian cloud-top cause periodic variations in both winds and ultraviolet (UV) brightness. While the wave candidates are the 4-day Kelvin wave and 5-day Rossby wave with zonal wavenumber 1, their temporal…

The convectively driven, weakly magnetized regions of the solar photosphere dominate the Sun's surface at any given time, but the temporal variations of these quiet regions of the photosphere throughout the solar cycle are still not well…

太阳与恒星天体物理 · 物理学 2025-05-05 James Crowley , Ivan Milic , Gianna Cauzzi , Kevin Reardon

We show that while the Fourier transform can figure only an "intensity" of a periodic signal, there is an additional information embedded, which is a "coherence" of the signal. Supposing that the periodicity is reflected only on the…

太阳与恒星天体物理 · 物理学 2022-02-07 Kim Chol-jun

This paper studies the dependence of the CaIIH line core brightness on the strength and inclination of photospheric magnetic field, and on the parameters of convective and wave motions in a facular region at the solar disc center. We use…

太阳与恒星天体物理 · 物理学 2016-04-06 R. Kostik , E. Khomenko

Measurements of low-order p modes and gravity modes are perturbed by the solar convective background. Such perturbation increases below 2mHz for intensity measurements and 1mHz for velocity measurements. While the low-degree modes have…

天体物理学 · 物理学 2008-10-10 R. A. Garcia , S. Mathur , I. Gonzalez Hernandez , A. Jimenez

Irradiance variability has been monitored from space for more than two decades. Even if data are coming from different sources, it is well established that a temporal variability exists which can be set to as approximately 0.1%, in phase…

天体物理学 · 物理学 2009-11-11 J. P. Rozelot , S. Lefebvre , S. Pireaux , A. Ajabshirizadeh

Supergranulation is a fluid-dynamical phenomenon taking place in the solar photosphere, primarily detected in the form of a vigorous cellular flow pattern with a typical horizontal scale of approximately 30--35~megameters, a dynamical…

太阳与恒星天体物理 · 物理学 2018-07-05 Francois Rincon , Michel Rieutord

We present a formalism for investigating the interaction between pmode oscillations and convection by analyzing realistic, three-dimensional simulations of the near-surface layers of the solar convection zone. By choosing suitable…

天体物理学 · 物理学 2009-10-31 Å. Nordlund , R. F. Stein

For the first time, a multi-wave research of oscillation dynamics in a solar facula from its birth to decay was carried out. We performed spectral observations of active region NOAA 12744 at Horizontal Solar Telescope of the Sayan Solar…

太阳与恒星天体物理 · 物理学 2020-08-26 Andrei Chelpanov , Nikolai Kobanov

Some observations suggest that solar spicules show small amplitude and high frequency oscillations of magneto-acoustic waves, which arise from photospheric granular forcing. We apply the method of MHD seismology to determine the period of…

天体物理学 · 物理学 2009-11-13 A. Ajabshirizadeh , E. Tavabi , S. Koutchmy

The goal of this research is to investigate how magnetic field affects the dynamics of granular convection and excitation of solar oscillations by means of realistic numerical simulations. We have used a 3D, compressible, non-linear…

天体物理学 · 物理学 2008-05-27 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

A 3D simulation of the upper part of the solar convective zone is used to derive constraints about the averaged and dynamic properties of solar turbulent convection. Theses constraints are then used to compute the acoustic energy supply…

天体物理学 · 物理学 2007-05-23 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

In addition to the well-known 11-year solar cycle, the Sun's magnetic activity also shows significant variation on shorter time scales, e.g. between one and two years. We observe a quasi-biennial (2-year) signal in the solar p-mode…

A new time--distance far-side imaging technique was recently developed by utilizing multiple multi-skip acoustic waves. The measurement procedure is applied to 11 years of Doppler observations from the Solar Dynamics Observatory /…

太阳与恒星天体物理 · 物理学 2022-01-05 Junwei Zhao , Grace Y. Jing , Ruizhu Chen

We study the response of the low-degree solar p-mode frequencies to the unusual extension of the minimum of solar surface activity since 2007. Helioseismic observations collected by the space-based, Sun-as-a-star GOLF instrument and by the…

太阳与恒星天体物理 · 物理学 2010-05-06 D. Salabert , R. A. Garcia , P. L. Palle , S. J. Jimenez-Reyes

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

Solar oblateness has been the subject of several studies dating back to the nineteenth century. Despite diffculties, both theoretical and observational, tangible results have been achieved. However, variability of the solar oblateness with…

太阳与恒星天体物理 · 物理学 2025-01-22 Jean P. Rozelot , Alexander G. Kosovichev , Ali Kilcik

Context. Solar gravity modes (g modes) are buoyancy waves trapped in the solar radiative zone that have been very difficult to detect at the surface. Solar g modes would complement solar pressure modes (p modes) in probing the central…

太阳与恒星天体物理 · 物理学 2019-09-04 Vincent G. A. Böning , Huanchen Hu , Laurent Gizon