English
Related papers

Related papers: Solar rotation rate and its gradients during cycle…

200 papers

The phenomenon of solar "torsional oscillations" (TO) represents migratory zonal flows associated with the solar cycle. These flows are observed on the solar surface and, according to helioseismology, extend through the convection zone. We…

Solar and Stellar Astrophysics · Physics 2016-08-31 G. Guerrero , P. K. Smolarkiewicz , E. M. de Gouveia Dal Pino , A. G. Kosovichev , N. N. Mansour

We compare the zonal flow pattern in subsurface layers of the Sun with the distribution of surface magnetic features like sunspots and polar faculae. We demonstrate that in the activity belt, the butterfly pattern of sunspots coincides with…

Astrophysics · Physics 2009-11-13 K. R. Sivaraman , H. M. Antia , S. M. Chitre , V. V. Makarova

The differential rotation of the sun, as deduced from helioseismology, exhibits a prominent radial shear layer near the top of the convection zone wherein negative radial gradients of angular velocity are evident in the low- and…

Astrophysics · Physics 2009-11-07 M. L. DeRosa , P. A. Gilman , J. Toomre

The Solar Cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway

To explore the physics of large-scale flows in solar-like stars, we perform 3D anelastic simulations of rotating convection for global models with stratification resembling the solar interior. The numerical method is based on an implicit…

Solar and Stellar Astrophysics · Physics 2013-12-10 G. Guerrero , P. K. Smolarkiewicz , A. G. Kosovichev , N. N. Mansour

Helioseismic inversions of the Sun's internal angular velocity profile show that the rotation changes from differential in latitude in the convection zone to almost uniform in the radiative region below. The transition occurs in a thin…

Astrophysics · Physics 2007-05-23 E. Schatzman , J. -P. Zahn , P. Morel

Low-degree solar p-mode observations from the long-lived Birmingham Solar Oscillations Network (BiSON) stretch back further than any other single helioseismic data set. Results from BiSON have suggested that the response of the mode…

Solar and Stellar Astrophysics · Physics 2018-07-18 R. Howe , W. J. Chaplin , G. R. Davies , Y. Elsworth , S. Basu , A. -M. Broomhall

We discuss the turbulent structure and dynamics of the upper solar convection zone using a 3D radiative hydrodynamic simulation model at 45 degrees latitude. The model reveals the self-formation of meridional flows, the leptocline, and the…

Solar and Stellar Astrophysics · Physics 2025-02-04 Irina N. Kitiashvili , Alan A. Wray

In this paper, we investigate the spatial distribution of solar flares in the northern and southern hemisphere of the Sun that occurred during the period 1996 to 2003. This period of investigation includes the ascending phase, the maximum…

Astrophysics · Physics 2009-11-11 Bhuwan Joshi , P. Pant , P. K. Manoharan

We determined the differential rotation (DR) parameters $A$ and $B$ (corresponding to the equatorial rotation velocity and the gradient of the solar DR) by tracing sunspot groups in sunspot drawings of the Kanzelh\"ohe Observatory for Solar…

An explanation is presented for the rather strong total surface differential rotation of the observed very young solar-type stars like AB Dor and PZ Tel. Due to its rapid rotation a nonuniform energy flux leaves the stellar core so that the…

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

Surface observations indicate that the speed of the solar meridional circulation in the photosphere varies in anti-phase with the solar cycle. The current explanation for the source of this variation is that inflows into active regions…

Solar and Stellar Astrophysics · Physics 2017-11-29 D. Passos , M. Miesch , G. Guerrero , P. Charbonneau

The solar convection zone rotates differentially, with its equatorial region rotating more rapidly than the polar regions. This form of differential rotation, also observed in many other low-mass stars, is understood to arise when Coriolis…

Solar and Stellar Astrophysics · Physics 2022-10-26 Maria E. Camisassa , Nicholas A. Featherstone

Meridional flow results from slight deviations from the thermal wind balance. The deviations are relatively large in the boundary layers near the top and bottom of the convection zone. Accordingly, the meridional flow attains its largest…

Solar and Stellar Astrophysics · Physics 2015-06-11 Leonid L. Kitchatinov

We find that the mean meridional motion of the spot groups varies considerably on a time scale of about 5-20 years. The maximum amplitude of the variation is about 10-15 m/s in both the Sun's northern and the southern hemispheres. Variation…

Solar and Stellar Astrophysics · Physics 2009-11-26 J. Javaraiah

We investigate the characteristics and the sources of the slow (< 450 km/s) solar wind during the four years (2006-2009) of low solar activity between Solar Cycles 23 and 24. We use a comprehensive set of in-situ observations in the…

Solar and Stellar Astrophysics · Physics 2016-10-05 E. K. J. Kilpua , M. S. Madjarska , N. Karna , T. Wiegelmann , C. Farrugia , W. Yu , K. Andreeova

The exact location of the solar dynamo remains uncertain--whether it operates primarily in the near-surface shear layer, throughout the entire convection zone, or near the tachocline, a region of sharp transition in the solar rotation,…

Solar and Stellar Astrophysics · Physics 2026-01-07 Krishnendu Mandal , Alexander G. Kosovichev

This paper describes a new way of determining the high-latitude solar rotation rate statistically from simultaneous observations of many polar faculae. In this experiment, I extracted frames from a movie made previously from flat-fielded…

Solar and Stellar Astrophysics · Physics 2024-11-05 Neil R. Sheeley

The present paper discusses results of a statistical study of the characteristics of coronal hole (CH) rotation in order to find connections to the internal rotation of the Sun. The goal is to measure CH rotation rates and study their…

The tachocline is believed to be the region where the solar dynamo operates. With over a solar cycle's worth of data available from the MDI and GONG instruments, we are in a position to investigate not merely the average structure of the…

Solar and Stellar Astrophysics · Physics 2015-05-28 H. M. Antia , Sarbani Basu