电导率分布、对流电场转向区与场向电流形态(模式分析)

本文利用一些简单模式讨论对流转向区形态、电离层电导率的分布变化对场向电流形态的影响。结果表明,一区场向电流是最基本的,与对流转向区直接相联。二区场向电流的产生不仅与对流电场的屏蔽相联,也与电导率变化有关。电导率的变化还可产生一区电流高纬侧的零区电流和二区电流低纬侧的反向电流。此外,剪切转向区和旋转转向区所对应的场向电流分布也有所不同。本文结果有助于理解观测的场向电流之复杂形态,也可以解释同样的行星际磁场状况下,场向电流的不同变化。 

The Distribution of the Ionospheric Conductivity,the Morphology of the Convection Reversal and the Feature of Birkeland Currents (Model Analysis)

The effect of the distribution of ionospheric conductivity and the morphology of the convection reversal on the feature of Birkeland currents is discussed by means of simple models.It is shown: the region 1 field-aligned current is the basic one and connected closely by with the convection reversal;the region 2 field-aligned current,on the other hand,is caused by the shielding of the convection field,or by the decrease of the ionospheric conductivity.The variation of the ionospheric conductivity can also cause the production of the so-called zero region field-aligned current poleward to the region 1 current,and the reverse current equator-ward to the region 2 current.The analysis also demonstrates that the current distribution connected with the rotation reversal is different from that connected with the shear reversal.The paper presented may contribute a little understanding of the complex feature of Birkeland current.It may also interpret the different distribution of field-aligned currents under same condition of the interplanetary magnetic field.