Dipole model of the Earth's magnetic field

About: Dipole model of the Earth's magnetic field is a research topic. Over the lifetime, 2756 publications have been published within this topic receiving 83021 citations.

Trapped particles in a distorted dipole field

Abstract: A dipole magnetic field is analytically compressed and extended to represent a possible effect of the solar wind on the earth's magnetic field on the day and night side of the earth in the earth-sun meridian plane. The first and second adiabatic invariants of particle motion are used to calculate the mirror points of constant energy particles in the compressed and extended fields. The results support and clarify work by previous investigators, showing that shifts in mirror points of particles moving from one field to the other are large at large distances and smaller at lower altitudes. The results are compared to the experimental findings of recent satellites. It is concluded that field distortion may be a major cause of the observed shift in mirror points, but that final resolution of the problem will depend on further determination of the magnetic field on the night side of the earth.

The practical application of the magnetic virial theorem

Abstract: We have performed simulated vector magnetograph observations to study the effects of random and systematic magnetic field measurement errors on the magnetic energies that may be estimated using the virial theorem.

Modulation of low-rigidity cosmic rays and the power spectrum of the interplanetary magnetic field in 1962 and 1965.

Abstract: Low rigidity cosmic ray modulation and interplanetary medium at solar minimum and at other phases of solar cycle

Electric potentials in magnetic dipole fields normal and oblique to a surface in plasma: Understanding the solar wind interaction with lunar magnetic anomalies

Abstract: [1] We experimentally investigated the solar wind interaction with moderate-strength lunar magnetic anomalies in which the electrons are magnetized but the ions remain unmagnetized. Previously, we studied the plasma sheaths above an insulating surface in a magnetic dipole field oriented parallel to the surface. In this paper, when the dipole field is oriented normal to the surface, the surface potential largely rises, and a potential bump forms in the sheath in the magnetic cusp region due to a significant magnetic mirror reflection of the electrons. It is also found that the electrons are shielded from the central dipole wings and diverted into the side of the wings. When the dipole field obliquely intersects the surface, an asymmetric potential distribution develops. Our experimental results indicate that lunar surface charging can be greatly modified in the magnetic anomaly regions, creating extreme local electrical environments.

MHD simulations of the global solar corona around the Halloween event in 2003 using the synchronic frame format of the solar photospheric magnetic field

Abstract: [1] We performed two time-relaxation magnetohydrodynamics (MHD) simulations of the solar corona: one uses the boundary map representing the solar surface magnetic field distribution before the Halloween event in 2003, and the other uses map representing the postevent distribution. The aims of this study are to test a new concept of a solar surface magnetic field map capable of representing a particular time of interest and to examine the coronal responses to the solar photospheric magnetic field changes occurring over a few days. We used a new mapping scheme named “synchronic frame” that can include the longitudinal shift caused by the solar differential rotation and the solar surface variations occurring at the time of interest. These two time-relaxation MHD simulations using the two maps are separately performed to numerically obtain the quasi steady states of the solar corona before and after the Halloween event. Comparisons of the simulated coronal magnetic field structures to the SOHO/EIT measurements show that the combinations of our mapping method and simulation model reproduce the changes of the coronal structures well. We also find that the consequences of solar surface variations can be seen in the plasma quantities in the solar corona. These results show the capability and importance of the solar surface magnetic field mapping scheme for better reconstruction of global coronal structures, parts of which are sensitive to the solar surface magnetic field variations.