地球主磁场电磁转矩导致的地球差异旋转

为探索驱动地球系统差异旋转的力源,选择整个地球作为研究对象,应用经典电磁学理论,分析地球固体介质中的电荷在地球主磁场中的运动特点,发现存在一个与地球自转方向相反的切向洛伦兹力.通过电荷与介质间的相互作用,切向洛伦兹力传递至介质迫使介质西漂.为探索地球差异旋转的规律,建立了地球薄圆筒圈层模型.应用经典物理学理论和方法推导出了地球主磁场电磁转矩及其产生的角加速度公式.研究得到四点主要结论:1)作用于半径不同的地球薄圆筒圈层的地球主磁场电磁转矩及其产生的角加速度绝对值不同:地轴及赤道附近圈层的小,其自转相对较快;半径等于3～(1/2)倍地球半径的薄圆筒圈层及其相邻圈层的大,其自转相对较慢.2)同一薄圆筒圈层中的差异旋转缘于介质的介电常数、阻力系数及质量密度的差异.3)地球差异旋转缘于地球的自转、正负电荷的非对等分布及介质的介电常数、阻力系数、质量密度的差异.4)地球差异旋转导致地壳运动,孕育地震,地球主磁场是地球差异旋转和地震孕育的敏感因子.

The earth's differential rotation caused by the electromagnetic torque of the earth's main magnetic field

As the earth’s main magnetic field is stationary relative to the earth’s axis,the earth autorotation drives the electrostatic charges to move along the vertical direction of the earth’s main magnetic field,and causes charged particles subject to Lorentz force.According to the right-hand screw rule,the Lorentz force lies in meridian plane,perpendicular to the earth’s rotation speed,with the directions of positively charged particles pointing to the earth’s axis and the negatively charged to the opposite in normal phase of geomagnetic field,while in abnormal phase,they point to the opposite.This force is proportional to the earth’s rotation speed and is referred to as normal Lorentz force. The normal Lorentz force forces the charges to drift along the normal and causes the normal drift velocity.Similarly,it is deduced that the Lorentz force,corresponding to the normal drift velocity of the charged particles,is always to the west along the tangent whether normal or abnormal phase of geomagnetic field.This force is proportional to the normal drift velocity and is referred to as tangent Lorentz force. The tangential Lorentz force causes charged particles to produce tangent acceleration,and thus forms westward drift which drives the solid medium containing charged particles drift westward.It hinders the earth’s rotation that the torque of the tangential Lorentz force relative to the earth’s axis,which is the electromagnetic torquen M of the earth’s main magnetic field.This leads to the earth’s rotation rate long-term slowdown in single-valued,as well as differential rotation of the earth. To explore the law of the earth’s differential rotation,the whole earth was studied as the object and the earth’s axis was as the central axis for the cylindrical coordinate system.With application of the classical physics theory and analyzing method,the formulas were deduced to calculate the rotary inertia J of thin cylinder in the earth’s sphere,the electromagnetic torque M acting on thin cylinder and the angular acceleration β caused by M.Please see the formulas(11),(18) and(19) respectively. The equations(18) and(19) show that as the earth rotates,the absolute values of the electromagnetic torque and the angular acceleration are different and the thin cylinders near the equator and the earth’s axis are small,their autorotations are faster relatively,while the thin cylinders with radius equal to 3～(1/2) times the earth’s radius or near it are large,their autorotations are slower relatively.This differential rotation causes lithosphere rupture and deformation,forms east-west riftzones and drags the plate drift. The equation(19) also shows that the differences of dielectric constant,drag coefficient,mass density of medium can also lead to differences in β.There are solid rocks,ocean waters and many other media in the earth and the dielectric constant,drag coefficient and mass density are quite different even within the same thin cylinder,therefore differential rotation can also be formed.This differential rotation causes lithosphere rupture and deformation,forms north-south riftzones and pushs the plate drift. If the east-west riftzones interlace the north-southerns,the earth’s lithosphere could be divided into several sections.So it can be inferred that the formation and drift of tectonic plates originate from the earth’s differential rotation. The equation(19) also shows that β is proportional to the fourth power of the magnetic induction intensity(Bo) of the earth’s main magnetic field.A small difference in Bo can lead to larger difference in β.So the earth’s differential rotation is sensitive to the earth’s main magnetic field. The earth’s main magnetic field is formed by the superposition of the magnetic fields of positive and negative charges.The spatial distribution of magnetic field of positive and negative charges are similar but in opposite directions.Near the reversal of the earth’s main magnetic field,the absolute values of their magnetic induction intensity would be equivalent in the same space,and thus their superposition would lead to significant difference in Bo.Obviously,earthquake is the result of the earth’s differential rotation,and the earth’s main magnetic field reversal may be the cause to frequent earthquakes on the globe. The source of power of the earth’s differential rotation comes from the electromagnetic torquen of the earth’s main magnetic field,which originates in the Lorentz force.The Lorentz force arises from the magnetic field and its charges’ speed.Here,the magnetic field refers to the earth’s main magnetic field,originating from the earth’s autorotation and non-equivalent distribution of positive and negative charges.The speed of charges relative to the magnetic field is caused by the earth’s rotation.Referring to the equation(19),it could be concluded that the earth’s differential rotation is caused by its autorotation,non-equivalent distribution of positive and negative charges,and the differences of the dielectric constant,drag coefficient and mass density of medium.