内外源S_q等效电流体系反演及其应用研究

发布时间：2018-05-09 08:19

本文选题：Sq等效电流体系 + 球谐分析　；参考：《中国地震局地震预测研究所》2015年硕士论文

【摘要】：中国大陆由于到受太平洋板块、印度板块和菲律宾海板块的挤压,地震断裂带十分活跃。频繁发生的地震给人民的生命、财产安全及国家经济的发展带来了巨大的灾难和损失。大量的观测资料表明,地震电磁辐射在地震的监测预报中起着重要的作用,利用电磁卫星观测技术提取地震异常现象也越来越受到国内外学者的关注。为建立地震立体监测系统,中国也启动了地震电磁卫星计划,预计于2016年发射运行。电离层是地球高层大气中被部分电离的区域,磁层位于电离层上方,其内的大气被全部电离。磁层-电离层在受太阳活动影响的同时还受到了地球本体及其低层大气的影响,具有复杂的物理化学耦合过程。高动态、多尺度及特殊的空间环境使得磁层-电离层电流体系的研究有着极大的复杂性,利用磁层-电离层电流体系研究地震异常信号目前还处于探索阶段。本文基于前人研究基础利用球谐分析原理构建内、外源Sq等效电流体系反演模型,并将其反演结果与F10.7cm太阳射电通量、地磁活动指数Dst进行对比分析,之后选取震前低点位移现象并对其前后固定时段内等效电流体系反演结果进行分析研究期望为地震电离层研究提供一定的技术理论支撑。文中选取INTERMAGNET全球地磁台网中所有台站2001年到2012年的数据利用球谐分析所构建的内、外源Sq等效电流体系模型进行反演,结合F10.7cm、Dst指数分析其与太阳活动性之间的关系,综合震例及震前地磁低点位移现象探索了内外源Sq电流体系与地磁低点位移现象之间的关联。论文主要得到的研究结论如下:(1)内、外源Sq等效电流体系北半球电流涡中心电流强度在每年7、8月份呈现峰值,而南半球则正好相反,明显呈现出Sq夏季大,冬季小的季节变化。这一现象表明Sq主要受控于太阳,且内源成分还受到地电导率的影响。(2)内、外源Sq等效电流体系南、北电流涡中心强度在磁暴期间明显增大随后迅速减小,同Dst指数、F10.7cm太阳射电流量均具有同步变化的规律;Sq等效电流体系南、北电流涡中心强度在磁暴较大且次数较少的年份的变化磁暴连续发生的年份更具规律性。北半球电流涡中心强度和Dst磁暴指数的对应关系明显强于南半球。(3)内、外源Sq等效电流体系南、北电流涡中心电流强度年均值与F10.7cm太阳射电流量具有相同的周期性,即太阳活动周期11年,且南、北半球外源Sq等效电流体系电流涡中心强度年均值与F10.7cm太阳射电流量年均值体现出极好的相关性,其相关系数分别达到0.93和0.90,内源场所展现的相关系数则远低于外源场,分别为0.63和0.79。(4)地磁低点位移发生当日,内、外源Sq等效电流体系电流涡中心强度会发生减小的现象,且在内源场上减小的幅度更剧烈,而这一现象在地磁平静日的北半球能够得到良好的体现,如2008年的5月9日、6月13日。此外,电流涡中心位置在低点位移发生时可能会有一个纬向的偏移,且在内源场上更明显,似乎说明低点位移与内源等效电流体系的关系更为密切。
[Abstract]:Due to the compression of the Pacific plate, the India plate and the Philippines Sea plate in the mainland of China, the seismic fault zones are very active. Frequent earthquakes have brought great disasters and losses to the people's life, property safety and the development of the national economy. A large number of observations show that the seismic electromagnetic radiation is in the monitoring and prediction of the earthquake. In order to establish an earthquake stereo monitoring system, China has also started an earthquake electromagnetic satellite program, which is expected to be launched in 2016. The ionosphere is a region of partial ionization of the earth's high gas, and the magnetosphere is located in ionization. Above the layer, the atmosphere in it is all ionized. The magnetosphere - ionosphere is influenced by the solar activity and is influenced by the earth and its lower atmosphere. It has complex physical and chemical coupling processes. High dynamic, multi scale and special space environment make the study of the magnetosphere ionosphere current system have great complexity. The magnetosphere ionospheric current system is still in the exploration stage. Based on the theory of spherical harmonic analysis, this paper uses the theory of spherical harmonic analysis to construct the inversion model of the foreign Sq equivalent current system, and compares the inversion results with the F10.7cm solar radiation flux and the geomagnetic activity index Dst, and then selects the low point before the earthquake. The displacement phenomenon and the analysis of the inversion results of the equivalent current system in the fixed time period are expected to provide some technical support for the seismic ionosphere research. In this paper, the data of all stations in the INTERMAGNET global geomagnetic network from 2001 to 2012 are used to use the internal Sq equivalent current system model built by the spherical harmonic analysis. The relationship between the activity of the solar activity and the relationship between the F10.7cm and the Dst index is analyzed. The correlation between the internal and external Sq current system and the geomagnetic low displacement phenomenon is explored by a comprehensive seismic example and the geomagnetic low displacement phenomenon before the earthquake. The main conclusions of this paper are as follows: (1) the current vortex center in the northern hemisphere of the exogenous Sq equivalent system The current intensity is peak in 7,8 month, while the southern hemisphere is just the opposite, obviously showing a small seasonal variation of Sq summer and winter. This phenomenon indicates that Sq is mainly controlled by the sun, and the internal components are also affected by the conductivity of the earth. (2) the external Sq equivalent current system is south, and the central intensity of the north electric flow vortex is obviously increased during the magnetic storm. Then it decreases rapidly, with the same Dst index, the F10.7cm solar radio flow rate has the regularity of synchronous change, and the Sq equivalent current system is south, the central intensity of the north electric current vortex is more regular in the year of the larger magnetic storm and less times, and the corresponding relationship between the current vortex center intensity and the Dst magnetic storm index in the northern hemisphere is obviously stronger. In the southern hemisphere. (3), in the south, the annual mean value of the central current intensity of the north electric current is the same as that of the F10.7cm solar radio flow, that is, the solar activity cycle is 11 years, and the annual mean of the current vortex center intensity of the external Sq equivalent current system in the northern hemisphere is in excellent phase with the average annual mean of the F10.7cm solar radio flow. The correlation coefficient is 0.93 and 0.90 respectively, and the correlation coefficient of the internal source is far lower than that of the external field, which is 0.63 and 0.79. (4) of the geomagnetic low point displacement on the same day, and the current vortex center intensity of the foreign Sq equivalent current system decreases, and the amplitude of the decrease is more intense in the internal source field, and this phenomenon is in the geomagnetic field. The northern hemisphere of the calm day can be well reflected, such as the May 9th 2008, and the June 13th. In addition, the center position of the current vortex may have a zonal migration when the low displacement occurs, and is more obvious in the inner source field, which seems to indicate that the relationship between the low displacement and the internal source equivalent current system is more closely.

【学位授予单位】：中国地震局地震预测研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P315.7

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