同全球导航卫星系统(global navigation satellite system, GNSS)获取电离层总电子含量(total electron content, TEC)数据相比,传统的电离层垂测、斜测等短波段数据具有特征参数丰富、高度分辨率高、历史数据多等优点。为利用电离层垂...同全球导航卫星系统(global navigation satellite system, GNSS)获取电离层总电子含量(total electron content, TEC)数据相比,传统的电离层垂测、斜测等短波段数据具有特征参数丰富、高度分辨率高、历史数据多等优点。为利用电离层垂测和斜测数据,研究地下核爆引起的电离层扰动。利用2016年1月6日朝鲜地下核试验当天的斜测、垂测数据分析电离层扰动现象。结果表明,本次地下核爆造成的行波电离层扰动为小尺度电离层扰动,传播速度为150.3~158.7 m/s。同时核爆发生后0.5 h在距离爆点421.4 km处,观测到F2层临界频率(critical frequency of the F2layer, foF2)较月中值增加了0.7 MHz,较1月5日、1月7日在协调世界时(coordinated universal time, UTC)2:00 UTC的增加了0.5 MHz,极有可能是地下核爆通过岩石圈-大气圈-电离层圈耦合机制造成电离层电子浓度增加。本文分析结果与其他文献资料非常吻合。由此可见,基于短波段电离层探测方式感知电离层扰动从而实现地下核爆炸事件的监测,是一种有效的核爆电离层效应监测手段,可与其他直接监测手段相印证,提高核爆事件监测能力。展开更多
地震瑞利波在沿地表传输时衰减很慢,其能量在远离震中的区域仍然能够激发大气和电离层扰动.本文利用中国境内的GPS接收机网络观测电离层总电子含量(total electron content,TEC),分析了2011年日本地震后在中国区域上空产生的电离层扰动...地震瑞利波在沿地表传输时衰减很慢,其能量在远离震中的区域仍然能够激发大气和电离层扰动.本文利用中国境内的GPS接收机网络观测电离层总电子含量(total electron content,TEC),分析了2011年日本地震后在中国区域上空产生的电离层扰动.研究发现,瑞利波的能量从地面经大气耦合传输到电离层高度,导致在中国区域上空电离层出现与瑞利波传播同步的TEC扰动.利用中东部的稠密接收机网络,还揭示了扰动的大尺度二维空间结构:瑞利波经过后产生的TEC扰动呈条带状,在中纬度地区沿西北—东南方向排列,而在低纬度大致为东西方向.条带的转向可能与地磁场作用下的中性-离子耦合过程有关,大气波动导致的等离子扰动倾向于沿磁力线方向(向南)传播,从而形成垂直磁力线方向(东西)的波前结构.这是首次在远离震中的区域使用GPS站网研究地震波耦合电离层扰动的大尺度二维空间结构.展开更多
电离层沿经度方向变化的3波(WN3)和4波(WN4)经度波数谱成分与高层大气中周日东向2波(DE2)和3波(DE3)潮汐模之间密切相关.利用由JPL全球电离层地图(GIM)数据计算出的总电子积分含量(TEC)的纬度积分ITEC,以及TIMED卫星搭载的TIDI仪器观测...电离层沿经度方向变化的3波(WN3)和4波(WN4)经度波数谱成分与高层大气中周日东向2波(DE2)和3波(DE3)潮汐模之间密切相关.利用由JPL全球电离层地图(GIM)数据计算出的总电子积分含量(TEC)的纬度积分ITEC,以及TIMED卫星搭载的TIDI仪器观测到的MLT(Mesopause and lower Thermosphere)高度上的大气水平风场,通过傅里叶变换提取出不同的电离层经度变化的波数谱成分和不同的大气潮汐模,比较了WN3和WN4等波数谱成分与DE2,DE3等潮汐模的年变化和年际变化,发现WN3,WN4的变化分别与DE2,DE3中纬向风分量的变化一致,而与其子午风分量没有明显的联系.通过进一步将电离层经度变化波数谱成分WN3和WN4分解为"潮汐模",结果显示"DE2"和"DE3"各自在WN3和WN4中起主导作用,它们的年变化和年际变化也同DE2,DE3潮汐类似.最后,复相关分析的结果表明电离层WN3中的"DE2"与大气DE2潮汐的纬向风分量在北半球有很好的相关性,电离层WN4中的"DE3"则与大气DE3潮汐的纬向风分量在整个中低纬地区相关程度很高;与此同时,子午风分量对电离层"DE2","DE3"的贡献很微弱.这些都说明大气DE2,DE3潮汐的纬向风分量是引起电离层WN3,WN4的重要因素.展开更多
In this paper, we focus on ionospheric absorption in the East Asia sector, and look for manifestations of atmospheric influences in this area. First, a 4-year historical record of absorption measurement at Beijing is ...In this paper, we focus on ionospheric absorption in the East Asia sector, and look for manifestations of atmospheric influences in this area. First, a 4-year historical record of absorption measurement at Beijing is presented. This record was obtained by a sweep frequency technique, in which 27-days periodic variation of the absorption level was found to be dominant, appearing in most seasons except winters. Instead, unusual enhancements of the absorption level appeared in winters (winter anomaly), at the meantime the level varied with periods mainly in the range of 8-12 days. Comparing to 27-days period from the Sun, the shorter period oscillations should be related to planetary wave activities in lower atmosphere. Second, fmin data from 5 mid-latitude ionosondes in Japan were used as an indirect but long-term measurement. With the fmin data covering two solar cycles, disturbances with various periods were found to be active around solar maximum years, but the 8-12 days oscillations always existed in winter, showing seasonal dependence instead of connection to solar activity. These results given in this paper demonstrate seasonal and solar cycle-dependent features of the ionospheric absorption in East Asia sector, and confirm the existence of influence from atmosphere-ionosphere coupling in this area, as well as the relationship between ionospheric winter anomaly and planetary wave activity.展开更多
文摘同全球导航卫星系统(global navigation satellite system, GNSS)获取电离层总电子含量(total electron content, TEC)数据相比,传统的电离层垂测、斜测等短波段数据具有特征参数丰富、高度分辨率高、历史数据多等优点。为利用电离层垂测和斜测数据,研究地下核爆引起的电离层扰动。利用2016年1月6日朝鲜地下核试验当天的斜测、垂测数据分析电离层扰动现象。结果表明,本次地下核爆造成的行波电离层扰动为小尺度电离层扰动,传播速度为150.3~158.7 m/s。同时核爆发生后0.5 h在距离爆点421.4 km处,观测到F2层临界频率(critical frequency of the F2layer, foF2)较月中值增加了0.7 MHz,较1月5日、1月7日在协调世界时(coordinated universal time, UTC)2:00 UTC的增加了0.5 MHz,极有可能是地下核爆通过岩石圈-大气圈-电离层圈耦合机制造成电离层电子浓度增加。本文分析结果与其他文献资料非常吻合。由此可见,基于短波段电离层探测方式感知电离层扰动从而实现地下核爆炸事件的监测,是一种有效的核爆电离层效应监测手段,可与其他直接监测手段相印证,提高核爆事件监测能力。
文摘地震瑞利波在沿地表传输时衰减很慢,其能量在远离震中的区域仍然能够激发大气和电离层扰动.本文利用中国境内的GPS接收机网络观测电离层总电子含量(total electron content,TEC),分析了2011年日本地震后在中国区域上空产生的电离层扰动.研究发现,瑞利波的能量从地面经大气耦合传输到电离层高度,导致在中国区域上空电离层出现与瑞利波传播同步的TEC扰动.利用中东部的稠密接收机网络,还揭示了扰动的大尺度二维空间结构:瑞利波经过后产生的TEC扰动呈条带状,在中纬度地区沿西北—东南方向排列,而在低纬度大致为东西方向.条带的转向可能与地磁场作用下的中性-离子耦合过程有关,大气波动导致的等离子扰动倾向于沿磁力线方向(向南)传播,从而形成垂直磁力线方向(东西)的波前结构.这是首次在远离震中的区域使用GPS站网研究地震波耦合电离层扰动的大尺度二维空间结构.
文摘电离层沿经度方向变化的3波(WN3)和4波(WN4)经度波数谱成分与高层大气中周日东向2波(DE2)和3波(DE3)潮汐模之间密切相关.利用由JPL全球电离层地图(GIM)数据计算出的总电子积分含量(TEC)的纬度积分ITEC,以及TIMED卫星搭载的TIDI仪器观测到的MLT(Mesopause and lower Thermosphere)高度上的大气水平风场,通过傅里叶变换提取出不同的电离层经度变化的波数谱成分和不同的大气潮汐模,比较了WN3和WN4等波数谱成分与DE2,DE3等潮汐模的年变化和年际变化,发现WN3,WN4的变化分别与DE2,DE3中纬向风分量的变化一致,而与其子午风分量没有明显的联系.通过进一步将电离层经度变化波数谱成分WN3和WN4分解为"潮汐模",结果显示"DE2"和"DE3"各自在WN3和WN4中起主导作用,它们的年变化和年际变化也同DE2,DE3潮汐类似.最后,复相关分析的结果表明电离层WN3中的"DE2"与大气DE2潮汐的纬向风分量在北半球有很好的相关性,电离层WN4中的"DE3"则与大气DE3潮汐的纬向风分量在整个中低纬地区相关程度很高;与此同时,子午风分量对电离层"DE2","DE3"的贡献很微弱.这些都说明大气DE2,DE3潮汐的纬向风分量是引起电离层WN3,WN4的重要因素.
基金supported by the National Natural Science Foundation of China (Grant No. 40904036)the Public Science and Technology Research Funds Projects of Ocean, State Oceanic Administration of China (Grant No. 201005017)+1 种基金the National Basic Research Program of China ("973" Project) (Grant No. 2011CB811405)the Specialized Research Fund for State Key Laboratories
文摘In this paper, we focus on ionospheric absorption in the East Asia sector, and look for manifestations of atmospheric influences in this area. First, a 4-year historical record of absorption measurement at Beijing is presented. This record was obtained by a sweep frequency technique, in which 27-days periodic variation of the absorption level was found to be dominant, appearing in most seasons except winters. Instead, unusual enhancements of the absorption level appeared in winters (winter anomaly), at the meantime the level varied with periods mainly in the range of 8-12 days. Comparing to 27-days period from the Sun, the shorter period oscillations should be related to planetary wave activities in lower atmosphere. Second, fmin data from 5 mid-latitude ionosondes in Japan were used as an indirect but long-term measurement. With the fmin data covering two solar cycles, disturbances with various periods were found to be active around solar maximum years, but the 8-12 days oscillations always existed in winter, showing seasonal dependence instead of connection to solar activity. These results given in this paper demonstrate seasonal and solar cycle-dependent features of the ionospheric absorption in East Asia sector, and confirm the existence of influence from atmosphere-ionosphere coupling in this area, as well as the relationship between ionospheric winter anomaly and planetary wave activity.
