【摘要】 震前地震孕育期地表异常增强的电场,通过大气电导率传输到电离层高度.该异常电场通过非稳态局部加热,可以在电离层高度激发声重波.基于该理论,利用一维时变中纬电离层物理模型,模拟了该扰动源对电离层电子密度的影响.结果表明,重力波引起的中性风速度扰动对电离层电子密度分布影响甚微,该机理无法解释震前电离层异常扰动现象.更多还原

【Abstract】 The study of the ionospheric disturbances prior to the occurrence of large earthquakes has attracted much attention for many years.However,until recently,the physical mechanism of seismo-ionospheric coupling is not fully understood.A strong perturbation of vertical electric field may take place within the epicentral zone a few days before strong earthquakes,which can penetrate into ionosphere through atmospheric conductivity.Acoustic gravity waves may be resulted from the non-stationary Joule heating of a local region above the epicentral zone of an imminent earthquake due to the anomalous electric field.Based on this mechanism and one-dimensional time physical model of ionosphere,the effect of acoustic gravity waves on ionosphere was calculated, which showed that the disturbance of horizontal neutral speed was too weak to have obvious effect on the ionosphere.This mechanism can not well interpret the ionospheric phenomena prior to strong earthquakes.Nevertheless,the electric field might modify ionospheric dynamic and electron density distribution through the effect of E×B.更多还原