Flip-flop transitions of the magnetic intensity and polarity reversals in the magnetohydrodynamic dynamo

被引：25

作者：

Kageyama, A ^{[1
]}

Ochi, MM ^{[1
]}

Sato, T ^{[1
]}

机构：

[1] Natl Inst Fus Sci, Theory & Comp Simulat Ctr, Toki 5095292, Japan

来源：

PHYSICAL REVIEW LETTERS | 1999年 / 82卷 / 26期

关键词：

D O I：

10.1103/PhysRevLett.82.5409

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Paleomagnetic data reveal that there have been a lot of geomagnetic field intensity transitions after stable polarity states of the time scales of 0.5 to 1 Myr. The transition time scale is of the order of 1000 years. When the dipole reversals take place, the intensity transition is always observed. On the contrary, there are many intensity transitions observed without dipole reversal. We have performed an extensive computer simulation of an MHD dynamo in a rotating spherical shell. The simulated magnetic field exhibits that generated magnetic energy experience a flip-hop type of transitions in its intensity. One transition is accompanied by the polarity reversal of the dipole component of the generated field, while the other two transitions are accompanied by the reversal of the octupole component.

引用

页码：5409 / 5412

页数：4

共 20 条

[1] THERMAL INSTABILITIES IN RAPIDLY ROTATING SYSTEMS [J].

BUSSE, FH .

JOURNAL OF FLUID MECHANICS, 1970, 44 (NOV26) :441-&

[2] NONLINEAR BOUSSINESQ CONVECTIVE MODEL FOR LARGE-SCALE SOLAR CIRCULATIONS [J].

GILMAN, PA .

SOLAR PHYSICS, 1972, 27 (01) :3-26

[3] INTERMEDIATE DYNAMO MODELS [J].

GLATZMAIER, GA ;

ROBERTS, PH .

JOURNAL OF GEOMAGNETISM AND GEOELECTRICITY, 1993, 45 (11-12) :1605-1616

[4] Rotation and magnetism of earth's inner core [J].

Glatzmaier, GA ;

Roberts, PH .

SCIENCE, 1996, 274 (5294) :1887-1891

[5] A 3-DIMENSIONAL SELF-CONSISTENT COMPUTER-SIMULATION OF A GEOMAGNETIC-FIELD REVERSAL [J].

GLATZMAIER, GA ;

ROBERTS, PH .

NATURE, 1995, 377 (6546) :203-209

[6] An anelastic evolutionary geodynamo simulation driven by compositional and thermal convection [J].

Glatzmaier, GA ;

Roberts, PH .

PHYSICA D-NONLINEAR PHENOMENA, 1996, 97 (1-3) :81-94

[7] A 3-DIMENSIONAL CONVECTIVE DYNAMO SOLUTION WITH ROTATING AND FINITELY CONDUCTING INNER-CORE AND MANTLE [J].

GLATZMAIER, GA ;

ROBERTS, PH .

PHYSICS OF THE EARTH AND PLANETARY INTERIORS, 1995, 91 (1-3) :63-75

[8] MORPHOLOGY OF THE GEOMAGNETIC-FIELD AND IMPLICATIONS FOR THE GEODYNAMO [J].

GUBBINS, D ;

BLOXHAM, J .

NATURE, 1987, 325 (6104) :509-511

[9] Generation mechanism of a dipole field by a magnetohydrodynamic dynamo [J].

Kageyama, A ;

Sato, T .

PHYSICAL REVIEW E, 1997, 55 (04) :4617-4626

[10] COMPUTER-SIMULATION OF A MAGNETOHYDRODYNAMIC DYNAMO .2. [J].

KAGEYAMA, A ;

SATO, T ;

WATANABE, K ;

HORIUCHI, R ;

HAYASHI, T ;

TODO, Y ;

WATANABE, TH ;

TAKAMARU, H .

PHYSICS OF PLASMAS, 1995, 2 (05) :1421-1431

← 1 2 →