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Waves connect all the layers of the Sun, from its interior to the upper atmosphere. It is becoming clear now the important role of magnetic field on the wave propagation. Magnetic field modifies propagation speed of waves, thus affecting…

Astrophysics · Physics 2015-05-13 Elena Khomenko

The activity of the Sun as a result of cyclic changes of the global magnetic field is studied. As a consequence of the analysis of magnetic activity of solar-type stars the following power dependencies were found: the dependence between the…

Solar and Stellar Astrophysics · Physics 2015-10-22 E. A. Bruevich , I. K. Rozgacheva

Solar p-mode oscillations are excited by the work of stochastic, non-adiabatic, pressure fluctuations on the compressive modes. We evaluate the expression for the radial mode excitation rate derived by Nordlund and Stein (Paper I) using…

Astrophysics · Physics 2009-10-31 R. F. Stein , Å. Nordlund

The mechanism that causes an interdecadal oscillation in a coarse resolution sector ocean model forced by mixed boundary conditions is studied. The oscillation is characterized by large fluctuations in convective activity and air/sea heat…

Atmospheric and Oceanic Physics · Physics 2008-02-03 G. Lenderink , R. J. Haarsma

Quasi-biennial oscillation (QBO) of solar magnetic activities is intrinsic to dynamo mechanism, but still far from fully understood. In this work, the phase and amplitude asymmetry of solar QBO of Halpha flare activity in the northern and…

Solar and Stellar Astrophysics · Physics 2019-10-16 L. H. Deng , X. J. Zhang , G. Y. Li , H. Deng , F. Wang

At the electron scales the power spectrum of solar-wind magnetic fluctuations can be highly variable and the dissipation mechanisms of the magnetic energy into the various particle species is under debate. In this paper we investigate data…

Evaluating the magnitude of natural climate variations is important because it can greatly affect future climate policies. As an example, we examine the influence of changes in solar activity (solar wind in particular) on surface…

Atmospheric and Oceanic Physics · Physics 2018-07-12 Kiminori Itoh , Shinya Matsuo , Hiroshi Serizawa , Kazuyoshi Yamashita , Takashi Amemiya

Context. Solar activity cycles vary in amplitude and duration. The variations can be at least partly explained by fluctuations in dynamo parameters. Aims. We want to restrict uncertainty in fluctuating dynamo parameters and find out which…

Solar and Stellar Astrophysics · Physics 2018-07-18 L. L. Kitchatinov , A. V. Mordvinov , A. A. Nepomnyashchikh

The parameters of the p-mode oscillations vary with solar activity. Such temporal variations provide insights for the study of the structural and dynamical changes occurring in the Sun's interior throughout the solar cycle. We present here…

Solar and Stellar Astrophysics · Physics 2015-05-20 David Salabert , Rafael A Garcia , Pere L Palle , Antonio Jimenez

To better understand the influence of the activity cycle on the solar atmosphere, we report the time variation of the radius observed at 37 GHz ($\lambda$=8.1 mm) obtained by the Mets\"ahovi Radio Observatory (MRO) through Solar Cycles 22…

Solar and Stellar Astrophysics · Physics 2019-12-17 Caius L. Selhorst , Juha Kallunki , C. G. Giménez de Castro , Adriana Valio , Joaquim E. R. Costa

The possibility has been suggested that high-frequency quasi-periodic oscillations observed in low-mass X-ray binaries are resonantly excited disk oscillations in deformed (warped or eccentric) relativistic disks (Kato 2004). In this paper…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Shoji Kato , Atsuo T. Okazaki , Finny Oktariani

We observe a new type of magneto-oscillations in the photovoltage and the longitudinal resistance of a two-dimensional electron system. The oscillations are induced by microwave irradiation and are periodic in magnetic field. The period is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 I. V. Kukushkin , M. Yu. Akimov , J. H. Smet , S. A. Mikhailov , K. von Klitzing , I. L. Aleiner , V. I. Falko

In this paper, we investigate the role of a high-frequency magnetic field in the resonant behavior displayed by a spin-$1/2$ particle under the influence of a rotating magnetic field. We propose two alternative methods for analyzing the…

Quantum Physics · Physics 2010-07-30 Jesús Casado-Pascual

Recent analysis of the helioseismic observations indicate that the previously observed surface torsional oscillations extend significantly downwards into the solar convection zone. In an attempt to understand these oscillations, we study…

Astrophysics · Physics 2007-05-23 Eurico Covas , Reza Tavakol , David Moss , Andrew Tworkowski

We investigate the evolution of subsurface flows during the emergence and the active phase of sunspot regions using the time-distance helioseismology analysis of the full-disk Dopplergrams from the Helioseismic and Magnetic Imager (HMI)…

Solar and Stellar Astrophysics · Physics 2024-12-25 Alexander G. Kosovichev , Viacheslav M. Sadykov

While magnetic field has only second order effects on global sound waves, it can affect the mode frequencies and flow fields inferred using local helioseismology. A strong localized field can bias our results when one try to infer global…

Solar and Stellar Astrophysics · Physics 2014-12-17 T. Corbard

The present study addresses the following questions: How representative of the actual velocities in the solar atmosphere are the Doppler shifts of spectral lines? How reliable is the velocity signal derived from narrowband filtergrams? How…

Solar and Stellar Astrophysics · Physics 2010-02-18 B. Fleck , T. Straus , M. Carlsson , S. M. Jefferies , G. Severino , T. D. Tarbell

The Sun is a variable star whose magnetic activity varies most perceptibly on a timescale of approximately 11 years. However, significant variation is also observed on much shorter timescales. We observe a quasi-biennial (2 year) signal in…

When exposed to a time-periodic chemical signal, an \textit{E.~coli} cell responds by modulating its receptor activity in a similar time-periodic manner. However, there exists a phase lag between the applied signal and the activity…

Biological Physics · Physics 2025-11-12 Ramesh Pramanik , Ramu K Yadav , Sakuntala Chatterjee

Recently, we have developed a method useful for mapping large-scale horizontal velocity fields in the solar photosphere. The method was developed, tuned and calibrated using the synthetic data. Now, we applied the method to the series of…

Astrophysics · Physics 2009-11-13 Michal Svanda , Mirek Klvana , Michal Sobotka , Vaclav Bumba
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