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Related papers: Supergranulation Scale Connection Simulations

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Like elsewhere in the deep-sea, life in the deep Mediterranean depends on turbulent exchange across the stable vertical density stratification for supply of nutrients and oxygen. Commonly modelled, turbulent exchange is inversely…

Atmospheric and Oceanic Physics · Physics 2023-11-23 Hans van Haren

Previous studies have discovered a population of small granules with diameters less than 800 km showing differing physical properties. High resolution simulations and observations of the solar granulation, in combination with automated…

Solar and Stellar Astrophysics · Physics 2017-02-15 Birgit Lemmerer , Arnold Hanslmeier , Herbert Muthsam , Isabell Piantschitsch

We explore the three-dimensional properties of convective, luminous ($L\approx10^{4.5}-10^{5}L_\odot$), Hydrogen-rich envelopes of Red Supergiants (RSGs) based on radiation hydrodynamic simulations in spherical geometry using…

Solar and Stellar Astrophysics · Physics 2022-05-04 Jared A. Goldberg , Yan-Fei Jiang , Lars Bildsten

We examine the role of stratification in determining the scale for turbulent anelastic convection. Motivated by the range of scales observed in convection at the solar photosphere, we perform local numerical simulations of convection for a…

Solar and Stellar Astrophysics · Physics 2019-04-03 M. Kessar , D. W. Hughes , E. Kersale , K. A. Mizerski , S. M. Tobias

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

The observed convective flows on the photosphere (e.g., supergranulation, granulation) play a key role in the Babcock-Leighton (BL) process to generate large-scale polar fields from sunspots fields. In most surface flux transport (SFT) and…

Solar and Stellar Astrophysics · Physics 2018-09-17 Gopal Hazra , Mark Miesch

Extending our recent studies of two-dimensional stellar convection to 3D, we compare three-dimensional hydrodynamic simulations to identically set-up two-dimensional simulations, for a realistic pre-main sequence star. We compare…

Solar and Stellar Astrophysics · Physics 2020-07-01 J. Pratt , I. Baraffe , T. Goffrey , C. Geroux , T. Constantino , D. Folini , R. Walder

Using grid refinement, we have simulated solar granulation in 2D. The refined region measures 1.97*2.58 Mm (vertical*horizontal). Grid spacing there is 1.82*2.84 km. The downflows exhibit strong Kelvin-Helmholtz instabilities. Below the…

Astrophysics · Physics 2009-11-13 H. J. Muthsam , B. Loew-Baselli , Chr. Obertscheider , M. Langer , P. Lenz , F. Kupka

Granulates are ubiquitous in nature and technology, but despite their great importance, their dynamics are by far less well understood than those of liquids. We demonstrate in an almost compactly filled flat (Hele-Shaw) cell, where slow…

Soft Condensed Matter · Physics 2017-06-23 Frank Rietz , Ralf Stannarius

Various models of solar sub-surface stratification are tested in the global EULAG-MHD solver to simulate diverse regimes of near-surface convective transport. Sub- and superadiabacity are altered at the surface of the model ($ r >…

Solar and Stellar Astrophysics · Physics 2019-11-19 Andrey M. Stejko , Gustavo Guerrero , Alexander G. Kosovichev , Piotr K. Smolarkiewicz

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…

Astrophysics · Physics 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

Turbulent and internal wave motions are important for the exchange of momentum, heat and suspended matter in the deep-sea which is generally stably stratified in density. Turbulence-generation models involve shear of vertical current…

Fluid Dynamics · Physics 2023-03-21 Hans van Haren

The influence of the basic rotation on anisotropic and inhomogeneous turbulence is discussed in the context of differential rotation theory. An improved representation for the original turbulence leads to a $\Lam$-effect which complies with…

Astrophysics · Physics 2009-11-11 L. L. Kitchatinov , G. Rüdiger

Several lines of evidence suggest that the velocity amplitude in global simulations of solar convection, U, may be systematically over-estimated. Motivated by these recent results, we explore the factors that determine U and we consider how…

Solar and Stellar Astrophysics · Physics 2016-09-21 Bridget O'Mara , Mark S. Miesch , Nicholas A. Featherstone , K. C. Augustson

Global 3D simulations of solar giant-cell convection have provided significant insight into the processes which yield the Sun's observed differential rotation and cyclic dynamo action. However, as we move to higher resolution simulations a…

Solar and Stellar Astrophysics · Physics 2018-06-13 Nicholas J. Nelson , Nicholas A. Featherstone , Mark S. Miesch , Juri Toomre

Two dimensional hydrodynamical simulations of convective oxygen burning shell in the presupernova evolution of a 20 solar-mass star are extended to later times. We used the VULCAN code to simulate longer evolution times than previously…

Astrophysics · Physics 2009-10-31 S. M. Asida , David Arnett

Emerging active regions are associated with convective flows on the spatial scale and lifetimes of supergranules. To understand how these flows are involved in the formation of active regions, we aim to identify where active regions emerge…

Solar and Stellar Astrophysics · Physics 2024-07-17 Hannah Schunker , William Roland-Batty , Aaron C. Birch , Douglas C. Braun , Robert H. Cameron , L. Gizon

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

In the surface layers of late-type stars, stellar convection is manifested with its typical granulation pattern due to the presence of convective motions. The resulting photospheric up- and downflows leave imprints in the observed spectral…

Solar and Stellar Astrophysics · Physics 2014-05-30 Zazralt Magic , Martin Asplund

We measure the eddy viscosity in the outermost layers of the solar convection zone by comparing the rotation law computed with the Reynolds stress resulting from f-plane simulations of the angular momentum transport in rotating convection…

Astrophysics · Physics 2016-08-16 G. Rüdiger , M. Küker , K. L. Chan
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