【摘要】 利用一维自洽的时变极区电离层模型,研究极隙区极光粒子沉降对极区电离层F层电子密度影响的时变过程。假设一维时变电离层模型描述的磁流管中F层等离子体在对流作用下经过极隙区,随对流路径的不同,磁流管在极隙区经历的时间不同,以此考察极光粒子沉降作用下电离层随时间的演化过程。数值计算结果表明,当磁流管在极隙区停留的时间足够长,F层电子密度能显著增大。然而在磁流管经历极隙区实际时间较短的情况下,极隙区极光粒子沉降对F层电子密度的影响并不大。本文还给出了统计对流模型作用下磁流管在经历极隙区时,有沉降粒子作用和没有沉降粒子作用两种情况下,F层等离子体的时间变化过程的差异。更多还原

【Abstract】 A simulation study on the effects of particle precipitation on the polar ionosphere was carried out in this paper.It was studied with the aid of a one-dimensional time-dependent ionospheric model self-consistently in the continuity,momentum and energy equations.With the model,flux tubes of plasma were followed in response to convection electric fields.The trajectories,which had been adopted to follow convecting plasma flux tubes was different from each other.When they convected through cusp region,the time that precipitating particle acting on the plasma flux tube was different.The result of simulation draw a conclusion that when the plasma flux tube stayed long enough in cusp region the electron density of ionospheric F layer would remarkably increase,while when the plasma flux tube stayed short in cusp region the electron density of ionospheric F layer would not remarkably increase.The other result was given by this paper from the other view.The assumption was that the precipitating electrons would act on a plasma flux tube,which convect through cusp region,or not.In the two situations the difference would come into being due to time transformation of electron density in the ionospheric F layer.更多还原