Changes in earth’s dipole

  title={Changes in earth’s dipole},
  author={Peter Olson and Hagay Amit},
The dipole moment of Earth’s magnetic field has decreased by nearly % MathType!Translator!2!1!AMS LaTeX.tdl!TeX -- AMS-LaTeX!% MathType!MTEF!2!1!+-% feaaeaart1ev0aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaGyoaiaacw% caaaa!3755!$$9\% $$ over the past 150 years and by about 30% over the… Expand
Gyre-driven decay of the Earth's magnetic dipole
It is found that meridional flux advection accounts for the majority of the dipole decay since 1840, especially during times of rapid decline, with magnetic diffusion making an almost steady contribution generally of smaller magnitude. Expand
Increasing exposure of geosynchronous orbit in solar wind due to decay of Earth's dipole field
The Earth's dipole moment has been decaying over the past 1.5 centuries. The magnetosphere thus has been shrinking and the chance of geosynchronous magnetopause crossings has been increasing. WeExpand
Local Estimation of the Earth's Core Magnetic Field
The geomagnetic field is generated in the Earth’s outer core by fluid motions in a process known as the geodynamo. During the past 18 years satellite magnetic measurements have provided new insightsExpand
Continuous millennial decrease of the Earth’s magnetic axial dipole
Abstract Since the establishment of direct estimations of the Earth's magnetic field intensity in the first half of the nineteenth century, a continuous decay of the axial dipole component has beenExpand
The reversed and normal flux contributions to axial dipole decay for 1880–2015
The axial dipole component of Earth’s internal magnetic field has been weakening since at least 1840, an effect widely believed to be attributed to the evolution of reversed flux patches (RFPs).Expand
Effects of Earth's magnetic field variation on high frequency wave propagation in the ionosphere
Abstract. The ionosphere is an anisotropic, dispersive medium for the propagation of radio frequency electromagnetic waves due to the presence of the Earth's intrinsic magnetic field and freeExpand
Geomagnetic dipole tilt changes induced by core flow
The tilt of the geomagnetic dipole decreased from about 11.7 ◦ in 1960 to 10.5 ◦ in 2005, following more than a century when it remained nearly constant. The recent poleward motion of the dipole axisExpand
Observational estimate of magnetic field and geodynamo parameters under the surface of the Earth’s core
For the first time, estimates (averaged in latitude and longitude) of the radial derivatives of the vortex magnetic field hidden directly under the surface of the Earth’s core were obtained on theExpand
Can Core Flows inferred from Geomagnetic Field Models explain the Earth's Dynamo?
We test the ability of velocity fields inferred from geomagnetic secular variation data to produce the global magnetic field of the Earth. Our kinematic dynamo calculations use quasi-geostrophic (QG)Expand
Earth’s magnetic field is probably not reversing
It is shown that neither excursion demonstrates field evolution similar to current changes in the geomagnetic field, which suggests that the current weakened field will also recover without an extreme event such as an excursion or reversal. Expand


Recent trends in the Earth's magnetic field
This work is an abridgment of a more extensive analysis of the earth's magnetic field based on observed data from the time of Gauss to the most recent epochs. An attempt was made to collect allExpand
The intensity of the Earth's magnetic field over the past 160 million years
In contrast to our detailed knowledge of the directional behaviour of the Earth's magnetic field during geological and historical times,, data constraining the past intensity of the field remainExpand
Intensity of the Earth's magnetic field in late Archean obtained from diabase dikes of the Slave Province, Canada
Abstract The geomagnetic field intensity in Late Archean times is evaluated from Archean diabase dikes intruded into the Yellowknife greenstone belt of the Slave Province, N.W.T., Canada. The dikeExpand
The role of the Earth's mantle in controlling the frequency of geomagnetic reversals
A series of computer simulations of the Earth's dynamo illustrates how the thermal structure of the lowermost mantle might affect convection and magnetic-field generation in the fluid core. EightExpand
Is Earth's magnetic field reversing?
Abstract Earth's dipole field has been diminishing in strength since the first systematic observations of field intensity were made in the mid nineteenth century. This has led to speculation that theExpand
Reversals of the Earth's Magnetic Field
Kawai and Hirooka1 have examined the results of archaeomagnetic observations, and those of secular variation, to investigate the movement of the geomagnetic dipole field during the past 2,000 yr.Expand
Global changes in intensity of the Earth's magnetic field during the past 800 kyr
Recent advances in palaeomagnetic and dating techniques have led to increasingly precise records of the relative intensity of the Earth's past magnetic field at numerous field sites. The compilationExpand
The steady part of the secular variation of the Earth's magnetic field
The secular variation of the Earth's magnetic field results from the effects of magnetic induction in the fluid outer core and from the effects of magnetic diffusion in the core and the mantle.Expand
The westward drift of the Earth's magnetic field
The westward drift of the non-dipole part of the earth’s magnetic field and of its secular variation is investigated for the period 1907-45 and the uncertainty of the results discussed. It is foundExpand
Changes in the Total Magnetic Energy External to the Earh's Core
The loss of magnetic energy accompanying the decrease in the earth's dipole field during the past 50 years has been shown by McDonald and Gunst to have been balanced by an equal increase in theExpand