Observations of poleward-propagating large-scale traveling ionospheric disturbances in southern China
Observations of poleward-propagating large-scale traveling ionospheric disturbances in southern China
复制标题
中国南方向极传播的大规模移动电离层扰动的观测
DOI：
10.5194/angeo-31-377-2013
复制
发表时间：
2013-01-01
影响因子：
1.9
通讯作者：
Xiong, B.
中科院分区：
文献类型：
--
作者：
Ding, F.;Wan, W.;Xiong, B.
摘要。本文报道了2011年5月27日至6月1日中国一次中等尺度风暴期间发生的两个极传播大尺度电离层扰动（LSTIDs）。这些观测是利用全球定位系统网络和中国和东南亚的电离层探空仪进行的。一个向东北方向传播的LSTID发生在5月30日上午，另一个发生在6月1日夜间。两个极行lstid都发生在华南低纬度地区（地磁纬度~ 7.3 ~ 24°N）风暴恢复阶段，并在由南向北传播过程中经历了严重的耗散。虽然夜间LSTID的初始相对振幅比早晨事件大60%左右，但由于夜间背景总电子含量（TEC）在风暴期间的强烈增强，夜间LSTID的消散速度比早晨事件快，这导致了傍晚强烈的离子阻力消散。与同一地区向赤道移动的lstid相比，极向传播的lstid表现出更窄的纬度范围、更小的振幅和略高的海拔。考虑到这些特征，极向传播的lstid可能是由中国南方附近的一些本地源激发的。在一些来自低层大气的初级中尺度扰动消散过程中，次级LSTIDs的激发是一种可能的机制。
Abstract. We report here on two cases of poleward-propagating large-scale traveling ionospheric disturbances (LSTIDs) in China during a medium-scale storm between 27 May and 1 June 2011. The observations were conducted by making use of the Global Positioning System network and ionosondes in China and Southeast Asia. One northeastward-propagating LSTID occurred on the morning of 30 May, while the other was observed during the nighttime of 1 June. Both poleward-traveling LSTIDs occurred during the storm's recovery phase in southern China's low-latitude region (geomagnetic latitude ~ 7.3–24° N) and experienced severe dissipation during their propagation from south to north. Although the initial relative amplitude of the nighttime LSTID was ~ 60% larger than that of the morning event, the nighttime event dissipated more quickly than the morning event because of a strong nighttime enhancement in background total electronic content (TEC) during storm time, which led to strong ion-drag dissipation during the evening. The poleward-propagating LSTIDs exhibit a narrower latitudinal range, a smaller amplitude, and a slightly higher elevation compared with the equatorward-moving LSTIDs observed in the same region. Given these features, the poleward-propagating LSTIDs were likely excited by some local source near southern China. Excitation of secondary LSTIDs during the dissipation of some primary medium-scale disturbances from the lower atmosphere is a possible mechanism.