Angular momentum transport in magnetized stellar radiative zones. IV. Ferraro's theorem and the solar tachocline

被引:95
作者
MacGregor, KB [1 ]
Charbonneau, P [1 ]
机构
[1] Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA
关键词
Sun : interior; Sun : oscillations; Sun : rotation;
D O I
10.1086/307389
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We consider the circumstances under which the latitudinal differential rotation of the solar convective envelope can (or cannot) be imprinted on the underlying radiative core through the agency of a hypothetical weak, large-scale poloidal magnetic field threading the solar radiative interior. We do so by constructing steady, two-dimensional axisymmetric solutions to the coupled momentum and induction equations under the assumption of a purely zonal flow and time-independent poloidal magnetic field. Our results show that the structure of the interior solutions is entirely determined by the boundary conditions imposed at the core-envelope interface. Specifically, in the high Reynolds number regime a poloidal held having a nonzero component normal to the core-envelope interface can lead to the transmission of significant differential rotation into the radiative interior. In contrast, for a poloidal field that is contained entirely within the radiative core, any differential rotation is confined to a thin magnetoviscous boundary layer located immediately beneath the interface, as well as along the rotation/magnetic axis. We argue that a magnetically decoupled configuration is more likely to be realized in the solar interior. Consequently, the helioseismically inferred lack of differential rotation in the radiative core does not necessarily preclude the existence of a weak, large-scale poloidal field therein. We suggest that such a field may well be dynamically significant in determining the structure of the solar tachocline.
引用
收藏
页码:911 / 917
页数:7
相关论文
共 25 条
[11]  
FERRARO VCA, 1937, MON NOT R ASTRON SOC, V97, P458
[12]   Joint instability of latitudinal differential rotation and toroidal magnetic fields below the solar convection zone [J].
Gilman, PA ;
Fox, PA .
ASTROPHYSICAL JOURNAL, 1997, 484 (01) :439-454
[13]   INFLUENCE OF AN AXIAL MAGNETIC FIELD ON STEADY LINEAR EKMAN BOUNDARY LAYER [J].
GILMAN, PA ;
BENTON, ER .
PHYSICS OF FLUIDS, 1968, 11 (11) :2397-&
[14]  
HUGHES WF, 1966, ELECTROMAGNETICS FLU
[15]   Helioseismic constraints on the gradient of angular velocity at the base of the solar convection zone [J].
Kosovichev, AG .
ASTROPHYSICAL JOURNAL, 1996, 469 (01) :L61-L64
[16]   ON SPIN-UP OF AN ELECTRICALLY CONDUCTING FLUID .2. HYDROMAGNETIC SPIN-UP BETWEEN INFINITE FLAT INSULATING PLATES [J].
LOPER, DE ;
BENTON, ER .
JOURNAL OF FLUID MECHANICS, 1970, 43 :785-&
[17]   MAGNETIC-FIELDS AND NONUNIFORM ROTATION IN STELLAR RADIATIVE ZONES [J].
MESTEL, L ;
WEISS, NO .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1987, 226 (01) :123-135
[18]   EVOLUTIONARY MODELS OF THE ROTATING SUN [J].
PINSONNEAULT, MH ;
KAWALER, SD ;
SOFIA, S ;
DEMARQUE, P .
ASTROPHYSICAL JOURNAL, 1989, 338 (01) :424-452
[19]   The slender solar tachocline: a magnetic model [J].
Rudiger, G ;
Kitchatinov, LL .
ASTRONOMISCHE NACHRICHTEN, 1997, 318 (05) :273-279
[20]  
SCHUSSLER M, 1994, ASTRON ASTROPHYS, V281, pL69