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Related papers: The Role of Downflows in Establishing Solar Near-S…

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We present a theoretical model of the near-surface shear layer (NSSL) of the Sun. Convection cells deeper down are affected by the Sun's rotation, but this is not the case in a layer just below the solar surface due to the smallness of the…

Solar and Stellar Astrophysics · Physics 2024-12-25 Arnab Rai Choudhuri , Bibhuti Kumar Jha

The advent of helioseismology has determined in detail the average rotation rate of the Sun as a function of radius and latitude. These data immediately reveal two striking boundary layers of shear in the solar convection zone (CZ): a…

Solar and Stellar Astrophysics · Physics 2019-03-06 Loren I. Matilsky , Bradley W. Hindman , Juri Toomre

We use global and local helioseismic inversions to explore the prevailing dynamical balances in the solar Near-Surface Shear Layer (NSSL). The differential rotation and meridional circulation are intimately linked, with a common origin in…

Solar and Stellar Astrophysics · Physics 2015-05-28 Mark S. Miesch , Bradley W. Hindman

We carry out an unprecedented high-resolution simulation for the solar convection zone. Our calculation reproduces the fast equator and near-surface shear layer (NSSL) of differential rotation and the near-surface poleward meridional flow…

Solar and Stellar Astrophysics · Physics 2025-04-09 H. Hotta

The radial gradient of the rotation rate in the near-surface shear layer (NSSL) of the Sun is independent of latitude and radius. Theoretical mean-field models have been successful in explaining this property of the solar NSSL, while global…

Solar and Stellar Astrophysics · Physics 2021-12-01 A. Barekat , M. J. Käpylä , P. J. Käpylä , E. P. Gilson , H. Ji

The Sun has a Near-Surface Shear Layer (NSSL), within which the angular velocity decreases rapidly with radius. We provide an explanation of this layer based on the thermal wind balance equation. Since convective motions are not affected by…

Solar and Stellar Astrophysics · Physics 2021-06-25 Bibhuti Kumar Jha , Arnab Rai Choudhuri

Helioseismology has revealed an increase in the rotation rate with depth in a thin ($\sim$30 Mm) near-surface layer. The normalized rotational shear in this layer is independent of latitude. This rotational state is shown to be a…

Solar and Stellar Astrophysics · Physics 2024-02-13 Leonid Kitchatinov

We present a high-resolution, highly stratified numerical simulation of rotating thermal convection in a spherical shell. Our aim is to study in detail the processes that can maintain a near surface shear layer (NSSL) as inferred from…

Solar and Stellar Astrophysics · Physics 2015-06-23 H. Hotta , M. Rempel , T. Yokoyama

Helioseismology has discovered a thin layer beneath the solar surface where the rotation rate increases rapidly with depth. The normalized rotational shear in the upper 10 Mm of the layer is constant with latitude. Differential rotation…

Solar and Stellar Astrophysics · Physics 2023-11-27 Leonid Kitchatinov

Understanding effects driven by rotation in the solar convection zone is essential for many problems related to solar activity, such as the formation of differential rotation, meridional circulation, and others. We analyze realistic 3D…

Solar and Stellar Astrophysics · Physics 2022-11-23 Irina N. Kitiashvili , Alexander G. Kosovichev , Alan A. Wray , Viacheslav M. Sadykov , Gustavo Guerrero

The discovery of the solar activity cycle was linked from the outset to the observation of the temporal variability of sunspots, which we know to be the result of complex processes associated with the dynamics of inner layers. Numerous…

Solar and Stellar Astrophysics · Physics 2025-03-04 Jean-Pierre Rozelot , Alexander Kosovichev , Irina Kitiashvili

As we approach solar convection simulations that seek to model the interaction of small-scale granulation and supergranulation and even larger scales of convection within the near-surface shear layer (NSSL), the treatment of the boundary…

Solar and Stellar Astrophysics · Physics 2015-05-20 Kyle Augustson , Mark Rast , Regner Trampedach , Juri Toomre

Using solar-cycle long helioseismic measurements of meridional and zonal flows in the near-surface shear layer (NSSL) of the Sun, we study their spatio-temporal variations and connections to active regions. We find that near-surface inflows…

Solar and Stellar Astrophysics · Physics 2025-12-16 Anisha Sen , S. P. Rajaguru , Abhinav Govindan Iyer , Ruizhu Chen , Junwei Zhao , Shukur Kholikov

Downflows on the solar surface are suspected to play a major role in the dynamics of the convection zone. We investigate the existence of the long-lasting downflows whose effects influence the interior of the Sun and the outer layers. We…

Solar and Stellar Astrophysics · Physics 2021-03-05 T. Roudier , M. Švanda , J. M. Malherbe , J. Ballot , D. Korda , Z. Frank

The gradient of rotation in the near-surface shear layer (NSSL) of the Sun provides valuable insights into the dynamics associated with the solar activity cycle and the dynamo. Results obtained with global oscillation mode-splittings lack…

Solar and Stellar Astrophysics · Physics 2024-04-04 M. Cristina Rabello Soares , Sarbani Basu , Richard Bogart

We present evidence of hitherto undiscovered global-scale oscillations in the near-surface shear layer of the Sun. These oscillations are seen as large scale variations of radial shear in both the zonal and meridional flows relative to…

Solar and Stellar Astrophysics · Physics 2023-07-05 Richard S. Bogart , Charles S. Baldner , Sarbani Basu , Rachel Howe , Maria Cristina Rabello Soares

Using time-distance local helioseismology flow maps within 1 Mm of the solar photosphere, we detect inflows toward activity belts that contribute to solar cycle scale variations in near-surface meridional flow. These inflows stretch out as…

Solar and Stellar Astrophysics · Physics 2023-06-28 Sushant S. Mahajan , Xudong Sun , Junwei Zhao

The outer surface layers of the sun show a clear deceleration at low latitudes. This is generally thought to be the result of a strong dominance of vertical turbulent motions associated with strong downdrafts. This strong negative radial…

Astrophysics · Physics 2009-11-13 Axel Brandenburg

We examine the linear behavior of three-dimensional Lagrangian displacements in a stratified, shearing background. The isentropic and iso-rotation surfaces of the equilibrium flow are assumed to be axisymmetric, but otherwise fully…

Solar and Stellar Astrophysics · Physics 2015-06-05 Steven A. Balbus , Emmanuel Schaan

A model of supra-arcade downflows (SADs), dark low density regions also known as tadpoles that propagate sunward during solar flares, is presented. It is argued that the regions of low density are flow channels carved by sunward-directed…

Space Physics · Physics 2015-06-16 P. A. Cassak , J. F. Drake , J. T. Gosling , T. -D. Phan , M. A. Shay , L. S. Shepherd
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