相关论文: Reversals of the solar dipole

Observations show that the photospheric solar magnetic dipole usually does not vanish during the reversal of the solar magnetic field, which occurs in each solar cycle. In contrast, mean-field solar dynamo models predict that the dipole…

The variable magnetic field of the solar photosphere exhibits periodic reversals as a result of dynamo activity occurring within the solar interior. We decompose the surface field as observed by both the Wilcox Solar Observatory and the…

Regardless of the physical origin of stellar magnetic fields - fossil or dynamo induced - an inclination angle between the magnetic and rotation axes is very often observed. Absence of observational evidence in this direction in the solar…

We argue that global magnetic field reversals similar to those observed in the Milky Way occur quite frequently in mean-field galactic dynamo models that have relatively strong, random, seed magnetic fields that are localized in discrete…

Based on data obtained from Wilcox Solar Observatiry the solar polar magnetic fields reversals in cycles 21\,--\,25 were considered. The results indicate that the polarity reversal occurs at the maximum of sunspot activity of each cycle,…

The shape and the dynamics of reversals of the magnetic field in a turbulent dynamo experiment are investigated. We report the evolution of the dipolar and the quadrupolar parts of the magnetic field in the VKS experiment, and show that the…

We report the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium. The magnetic field randomly switches between two symmetric solutions B and -B. We…

Periodic changes in a stellar magnetic field can be explained in two ways: the oblique rotator model or the solar cycle model. Although many papers favor the oblique rotator model, there has not been enough evidence to rule out the solar…

We considered variations the dipole and the quadrupole components of the solar large-scale magnetic field. Both the axial and the equatorial dipoles exhibit a systematic decrease in the past four cycles in accordance with the general…

Observations of the sun suggest that solar activities systematically create north-south hemispheric asymmetries. For instance, the hemisphere in which the sunspot activity is more active tends to switch after the early half of each solar…

Solar magnetic fields comprise an 11-year activity cycle, represented by the number of sunspots. The maintenance of such a solar magnetic field can be attributed to fluid motion in the convection zone, i.e. a dynamo. This study conducts the…

Context. Solar activity cycles vary in amplitude and duration. The variations can be at least partly explained by fluctuations in dynamo parameters. Aims. We want to restrict uncertainty in fluctuating dynamo parameters and find out which…

The polar field reversal is a crucial process in the cyclic evolution of the large-scale magnetic field of the Sun.Various important characteristics of a solar cycle, such as its duration and strength, and also the cycle predictability, are…

We show that a model, recently used to describe all the dynamical regimes of the magnetic field generated by the dynamo effect in the VKS experiment [1], also provides a simple explanation of the reversals of Earth's magnetic field, despite…

Numerical simulations of the geodynamo in presence of an heterogeneous heating are presented. We study the dynamics and the structure of the magnetic field when the equatorial symmetry of the flow is broken. If the symmetry breaking is…

The mean-field dynamics of an electric dipole moment in a deterministic and a fluctuating electric field is solved to obtain the average over fluctuations of the dipole moment and the angular mo- mentum as a function of time for a Gaussian…

Ground-state fluctuations reduce the zero-temperature magnetic moments of the spins in a quantum antiferromagnet. In the neighborhood of surfaces, interfaces, and other defects which break translational symmetry, these fluctuations are not…

This paper presents an analysis on the distribution of periods between consecutive reversals of the Earth's magnetic field. The analysis includes the randomness of polarities, whether the data corresponding to different periods belong to a…

We investigate various properties associated with the tilt of isolated magnetic bipoles in magnetograms taken at the solar surface. We show that bipoles can be divided into two groups which have tilts of opposite signs, and reveal similar…

Field reversals are the most spectacular changes in the geomagnetic field but remain little understood. Paleomagnetic data primarily constrain the reversal rate and provide few additional clues. Reversals and excursions are characterized by…