English
Related papers

Related papers: Equatorial magnetohydrodynamic shallow water waves…

200 papers

We derive analytical solutions and dispersion relations of global magnetic Poincar\'e (magneto-gravity) and magnetic Rossby waves in the approximation of shallow water magnetohydrodynamics. The solutions are obtained in a rotating spherical…

Astrophysics · Physics 2015-05-13 T. V. Zaqarashvili , R. Oliver , J. L. Ballester

Annual oscillations have been detected in many indices of solar activity during many cycles. Recent multi spacecraft observations of coronal bright points revealed slow retrograde toroidal phase drift (with the speed of 3 m/s of 1 yr…

The activity of Sun-like stars is governed by the magnetic field, which is believed to be generated in a thin layer between convective and radiative envelopes. The dynamo layer, also called the tachocline, permits the existence of Rossby…

Solar and Stellar Astrophysics · Physics 2025-10-13 T. V. Zaqarashvili , M. Dikpati , P. A. Gilman

Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This…

Solar and Stellar Astrophysics · Physics 2014-11-20 T. V. Zaqarashvili , M. Carbonell , R. Oliver , J. L. Ballster

The influence of a toroidal magnetic field on the dynamics of Rossby waves in a thin layer of ideal conductive fluid on a rotating sphere is studied in the "shallow water" magnetohydrodynamic approximation for the first time. Dispersion…

Astrophysics · Physics 2009-11-13 T. V. Zaqarashvili , R. Oliver , J. L. Ballester , B. M. Shergelashvili

Quasi-biennial oscillations (QBO) are frequently observed in the solar activity indices. However, no clear physical mechanism for the observed variations has been suggested so far. Here we study the stability of magnetic Rossby waves in the…

Solar and Stellar Astrophysics · Physics 2015-05-20 T. V. Zaqarashvili , M. carbonell , R. Oliver , J. L. Ballester

Long-term records of sunspot number and concentrations of cosmogenic radionuclides (10Be and 14C) on the Earth reveal the variation of the Sun's magnetic activity over hundreds and thousands of years. We identify several clear periods in…

Solar and Stellar Astrophysics · Physics 2015-06-03 T. V. Zaqarashvili , R. Oliver , A. Hanslmeier , M. Carbonell , J. L. Ballester , T. Gachechiladze , I. G. Usoskin

Rapidly rotating stars show short-period oscillations in magnetic activity and polar appearance of starspots. The aim of this paper is to study large-scale shallow water waves in the tachoclines of rapidly rotating stars and their…

Solar and Stellar Astrophysics · Physics 2015-05-28 T. V. Zaqarashvili , R. Oliver , J. L. Ballester , M. Carbonell , M. L. Khodachenko , H. Lammer , M. Leitzinger , P. Odert

Over the past decade, solar equatorial Rossby waves have been unambiguously identified and are considered potential diagnostics of solar interior dynamics. We investigate their inclined structure and temporal evolution in the solar interior…

Solar and Stellar Astrophysics · Physics 2026-01-12 Oana Vesa , Junwei Zhao , Ruizhu Chen

In this paper, we have studied the convectively coupled equatorially trapped waves in rotating stars, with and without magnetic field. The equatorial trapped HD and MHD Poincar\'e, Rossby, mixed Rossby-Poincar\'e, and Kelvin waves were…

Solar and Stellar Astrophysics · Physics 2021-10-01 Tao Cai , Cong Yu , Xing Wei

Several recent studies utilizing different helioseismic methods have confirmed the presence of large-scale vorticity waves known as solar Rossby waves within the Sun. Rossby waves are distinct from acoustic waves, typically with longer…

Solar and Stellar Astrophysics · Physics 2023-08-15 M. Waidele , Junwei Zhao

Can atmospheric waves in planet-hosting solar-like stars substantially resonate to tidal forcing? Substantially at a level of impacting the space weather or even of being dynamo-relevant? In particular, low-frequency Rossby waves, which…

Solar and Stellar Astrophysics · Physics 2023-02-22 G. M. Horstmann , G. Mamatsashvili , A. Giesecke , T. V. Zaqarashvili , F. Stefani

We study the properties of plasma oscillations in the solar tachocline using shallow-water magnetohydrodynamic equations. These oscillations are expected to correlate with solar activity. We find new qualitative features in the equatorial…

Solar and Stellar Astrophysics · Physics 2024-01-17 Ruben Lier , Richard Green , Jan de Boer , Jay Armas

We present a linear analysis of inviscid, incompressible, magnetohydrodynamic (MHD) shallow water systems. In spherical geometry, a generic property of such systems is the existence of five wave modes. Three of them (two magneto-Poincare…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Kevin Heng , Anatoly Spitkovsky

Turbulence and large-scale waves in the tropical region are studied using the spherical shallow water equations. With mesoscale vorticity forcing, both moist and dry systems show kinetic energy scaling that is dominated by rotational modes,…

Atmospheric and Oceanic Physics · Physics 2021-04-28 J. Schröttle , D. L. Suhas , N. Harnik , J. Sukhatme

We investigate the characteristics of equatorial waves associated with the maintenance of superrotation in the stratosphere of a Titan general circulation model. A variety of equatorial waves are present in the model atmosphere, including…

Earth and Planetary Astrophysics · Physics 2023-07-14 Neil T. Lewis , Nicholas A. Lombardo , Peter L. Read , Juan M. Lora

To understand magnetic diffusion, momentum transport, and mixing in the interior of the sun, we consider an idealized model of the tachocline, namely magnetohydrodynamics (MHD) turbulence on a $\beta$ plane subject to a large scale shear…

Astrophysics · Physics 2011-02-11 Nicolas Leprovost , Eun-Jin Kim

The Sun's complex dynamics is controlled by buoyancy and rotation in the convection zone and by magnetic forces in the atmosphere and corona. While small-scale solar convection is well understood, the dynamics of large-scale flows in the…

Context. Solar Rossby waves (r modes) have recently been discovered in the near-surface horizontal flow field using the techniques of granulation-tracking and ring-diagram analysis applied to six years of SDO/HMI data. Aims. Here we apply…

Solar and Stellar Astrophysics · Physics 2019-06-05 Zhi-Chao Liang , Laurent Gizon , Aaron C. Birch , Thomas L. Duvall

Eclipsing time variations have been observed for a wide range of binary systems, including post-common-envelope binaries. A frequently proposed explanation, apart from the possibility of having a third body, is the effect of magnetic…

‹ Prev 1 2 3 10 Next ›