强震前带电气溶胶逸出对电离层电场的影响  

Effects of Abnormal Aerosol Escaped from the Earth on Electric Field in the Ionosphere Before Strong Earthquakes

作　　者：卓俊[1] 牛胜利[1] 潘常周[1] 靳平[1] 

机构地区：[1]西北核技术研究所,西安710024

出　　处：《现代应用物理》2015年第3期225-231,共7页Modern Applied Physics

摘　　要：采用准静态模型近似描述地表异常电场传播到电离层的过程,建立了强震前带电气溶胶排放产生的附加电流,造成大气层-电离层传导电流扰动,最终造成电离层中电场扰动的计算方法;分析了电离层中电场发生明显扰动的区域大小与带电气溶胶排放参数的对应关系,并根据我国川滇地区和大华北地区强震等震线的特点,计算了不同等震线长短轴比值下,电离层中电场扰动面积随地震震级及带电气溶胶数密度的变化规律。结果表明:强震前气溶胶浓度远大于能引起电离层异常的最小气溶胶浓度值,会在地表处产生一个幅值小于100V·m-1的异常电场,并在电离层内产生幅值大于10mV·m-1的扰动电场;在相同气溶胶粒子数密度和相同震级条件下,等震线长短轴的比值k越小,电离层中电场异常区域越大。This paper presents the discussion of the possible physical mechanism of iono- sphere anomalies caused by charged aerosol escaped from the earthquake regions before strong earthquakes. The propagation of the external electric current resulted from charged aerosol was investigated in quasi-static approximation. The electro-dynamic model and com- putational method for disturbances of electric field in ionosphere caused by the external elec- tric current were built. Relationships between electric filed perturbations in ionosphere and characteristic parameters of aerosols injected before strong earthquake have been obtained. Moreover, the areas of electric field perturbation in ionosphere for different magnitudes of earthquakes and aerosol number densities in Sichuan-Yunnan areas and North China have been numerically calculated. The results show that the aerosol number densities before strong earthquakes are much larger than the least number density which can cause electric field disturbance in ionosphere. It has been found that the vertical component of abnormal electric filed on the earth surface is less than 100 V. m 1, and the horizontal component of electric field in the ionosphere is up to 10 mV. m-1. The area of disturbance region of electric field in ionosphere increases as the ratio of the length to the width of isoseismic line decreases.

关 键 词：带电气溶胶 地表异常电场 电离层异常 

分 类 号：P315.72[天文地球—地震学]