全球电离层VLF电场功率谱特征  

The global characteristics of VLF electric field frequency spectrum in ionosphere

作　　者：姚丽[1,2] 陈化然[1] 刘晓灿[1] 何宇飞[1] 

机构地区：[1]中国地震局地球物理研究所,中国北京100081 [2]中国科学院空间天气学国家重点实验室,中国北京100190

出　　处：《地震地磁观测与研究》2011年第4期27-34,共8页Seismological and Geomagnetic Observation and Research

基　　金：国家科技支撑项目(2008BAC35B01);中国科学院空间天气学国家重点实验室开放课题(08262DAA4S);中国地震局地球物理研究所基本科研专项(059902)共同资助

摘　　要：分析2006年3月至2009年2月DEMETER卫星VI.F电场功率谱数据发现,卫星高度上全球电离层电场功率谱有以下特征:高纬度区域电场辐射强度平均高于低纬度区域,几个地磁场异常区相应的电场辐射增强;全球电场功率谱,向阳侧强于夜侧,大陆强于海洋,夏季强于分点季,冬季最弱;不同频段的电场功率谱特征有显著差异,某些频段的功率谱有明显沿磁壳指数L线或地磁场线分布的特征;此外,不同年份、相同季节的电场功率谱全球分布特征及功率谱强度有较高相似度。该电离层全球观测模型将为地震电离层异常分析研究提供背景依据。By analyzing the electric field power spectrum data observed by the DEMETER satellite during the time interval of March 2006 and February 2009, it is found that the characteristics of Electric field power spectrum of global ionosphere in DEMETER altitude are as follows. electric field emission is more stronger in the region with high latitude than that in the low latitude in average, furthermore, the electric field emission enhanced corresponding to several geomagnetic field abnormal regions; global electric field power spectrum intensity is stronger on the dayside than on the nightside, stronger over the continents than over the ocean, stronger in the summer than in the equinoctial season, and the weakest in the winter; there exist prominent difference of electric field power spectrum in different frequency band, meanwhile, power spectrum distributes visibly along the magnetic shell index L shells or geomagnetic field intensity lines in some frequency bands; moreover, the global characteristics are more similar in the same season of different years. This global observation model will provide a basis for the study of ionosphere anomalies induced by seismic activity.

关 键 词：DEMETER卫星观测 电离层 VLF电场功率谱 全球背景特征 

分 类 号：P315.72[天文地球—地震学]