Simulations of a Quasi-Taylor State Geomagnetic Field Including Polarity Reversals on the Earth Simulator

Science ◽  
2005 ◽  
Vol 309 (5733) ◽  
pp. 459-461 ◽  
Author(s):  
F. Takahashi
Keyword(s):  
Geomagnetic Field ◽  
The Earth ◽  
Polarity Reversals

Paleomagnetism of the Great Slave Supergroup, Northwest Territories, Canada: the Stark Formation

1976 ◽  
Vol 13 (4) ◽  
pp. 563-578 ◽  
Author(s):  
D. K. Bingham ◽  
M. E. Evans
Keyword(s):  
Northwest Territories ◽  
North American ◽  
Geomagnetic Field ◽  
Pole Position ◽  
The West ◽  
Stratigraphic Sequence ◽  
Polar Wander ◽  
Early Proterozoic ◽  
The North ◽  
Polarity Reversals

Paleomagnetic results from 55 sampling sites throughout the Stark Formation are reported. The known stratigraphic sequence of these sites enables the behaviour of the geomagnetic field in these remote times (1750 m.y.) to be elucidated. Two polarity reversals are identified and these represent potentially useful correlative features in strata devoid of index fossils. One of these is investigated in detail and indicates that behaviour of the geomagnetic field during polarity reversals was essentially the same in the early Proterozoic as it has been over the last few million years. The pole position (145°W, 15°S, dp = 3.5, dm = 6.9) lies far to the west of that anticipated from earlier results, implying further complexity of the North American polar wander curve. Possible alternatives to this added complexity are discussed.

scholarly journals Eigenmode analysis of ballooning perturbations in the inner magnetosphere of the Earth

2007 ◽  
Vol 25 (6) ◽  
pp. 1391-1403 ◽  
Author(s):  
A. S. Parnowski
Keyword(s):  
Stability Criterion ◽  
Geomagnetic Field ◽  
Finite Conductivity ◽  
Nonlinear Structures ◽  
Magnetic Hydrodynamics ◽  
Longitudinal Displacement ◽  
Inner Magnetosphere ◽  
Transversal Displacement ◽  
The Earth ◽  
Eigenmode Analysis

Abstract. We analyze coupled Alfvén and slow magnetosonic eigenmodes in a dipole geomagnetic field with different ionospheric conductivities in the framework of ideal magnetic hydrodynamics (MHD) with finite pressure. We use numerical and, if possible, analytical methods to describe eigenmode frequencies, growth rates and eigenfunctions. The spectrum of Alfvén and slow magnetosonic modes is discrete and equidistant. The frequencies of the first Alfvén and slow magnetosonic eigenmodes are estimated as ~1 Hz and ~1 mHz, respectively. In the case of finite conductivity, periodic and aperiodic modes are separated and their interaction analyzed. It was shown that periodic and aperiodic perturbations can mutually transform into each other. A new flute stability criterion is derived (α~4.25), which is stricter than the Gold criterion (α=20/3). Here, as usual, α=−L/p dp/dL. For flute perturbations, the deviations of transversal displacement from a constant are calculated. An approximation for longitudinal displacement is derived. We determined the position of the main longitudinal peak, which can be responsible for nonlinear structures observed by Freja. An influence of nonlinear terms in pressure is estimated as well.

AN ANALYTICAL SOLUTION OF THE COSMIC RAYS TRANSPORT EQUATION IN THE PRESENCE OF THE GEOMAGNETIC FIELD

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1645-1653
Author(s):  
MARINA GIBILISCO
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Analytical Solution ◽  
Transport Equation ◽  
Geomagnetic Field ◽  
The Earth ◽  
Factorization Technique ◽  
Diffusion Motion ◽  
Geomagnetic Fields ◽  
The Magnetic Field

In this work, I study the propagation of cosmic rays inside the magnetic field of the Earth, at distances d ≤ 500 Km from its surface; at these distances, the geomagnetic field deeply influences the diffusion motion of the particles. I compare the different effects of the interplanetary and of the geomagnetic fields, by also discussing their role inside the cosmic rays transport equation; finally, I present an analytical method to solve such an equation through a factorization technique.

Variation in the rotation rate of the earth and the geomagnetic field

2007 ◽  
Vol 42 (4) ◽  
pp. 433-448 ◽  
Author(s):  
P. Varga ◽  
Z. Bus ◽  
B. Süle ◽  
A. Schreider ◽  
C. Bizouard ◽  
...  
Keyword(s):  
Rotation Rate ◽  
Geomagnetic Field ◽  
The Earth

scholarly journals Multidecadally resolved polarity oscillations during a geomagnetic excursion

2018 ◽  
Vol 115 (36) ◽  
pp. 8913-8918 ◽  
Author(s):  
Yu-Min Chou ◽  
Xiuyang Jiang ◽  
Qingsong Liu ◽  
Hsun-Ming Hu ◽  
Chung-Che Wu ◽  
...  
Keyword(s):  
20Th Century ◽  
Geomagnetic Field ◽  
Early 20Th Century ◽  
Human Society ◽  
Before Present ◽  
Earth History ◽  
Geomagnetic Excursion ◽  
Deep Interior ◽  
Polarity Reversals ◽  
Chinese Stalagmite

Polarity reversals of the geomagnetic field have occurred through billions of years of Earth history and were first revealed in the early 20th century. Almost a century later, details of transitional field behavior during geomagnetic reversals and excursions remain poorly known. Here, we present a multidecadally resolved geomagnetic excursion record from a radioisotopically dated Chinese stalagmite at 107–91 thousand years before present with age precision of several decades. The duration of geomagnetic directional oscillations ranged from several centuries at 106–103 thousand years before present to millennia at 98–92 thousand years before present, with one abrupt reversal transition occurring in one to two centuries when the field was weakest. These features indicate prolonged geodynamo instability. Repeated asymmetrical interhemispheric polarity drifts associated with weak dipole fields likely originated in Earth’s deep interior. If such rapid polarity changes occurred in future, they could severely affect satellites and human society.

scholarly journals Clustering of Polarity Reversals of the Geomagnetic Field

2006 ◽  
Vol 96 (12) ◽  
Author(s):  
V. Carbone ◽  
L. Sorriso-Valvo ◽  
A. Vecchio ◽  
F. Lepreti ◽  
P. Veltri ◽  
...  
Keyword(s):  
Geomagnetic Field ◽  
Polarity Reversals

Reducing the negative impact of changes in space weather on human condition

2019 ◽  
pp. 236-239
Author(s):  
E. V. Martysh
Keyword(s):  
Human Body ◽  
Space Weather ◽  
Geomagnetic Field ◽  
High Efficiency ◽  
Negative Impact ◽  
The State ◽  
Human Condition ◽  
Physical Factors ◽  
Plasma Medicine ◽  
The Earth

In the article, based on the analysis of the physical factors responsible for the parameters of space weather near the Earth, possible ways of influence of the geomagnetic field disturbances on the state of the human body and methods of untraditional medicine to prevent the negative impact of such disturbances, the conclusions about the possibility of using acupuncture in the prevention and elimination of such influence are made. and the ability to use plasma medicine to address these problems with high efficiency.

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