News from the Lower Ionosphere: A Review of Recent Developments
News from the Lower Ionosphere: A Review of Recent Developments
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来自低层电离层的新闻：近期发展回顾
DOI：
10.1007/s10712-009-9074-2
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发表时间：
2009
影响因子：
4.6
通讯作者：
M. Rapp
中科院分区：
文献类型：
--
作者：
M. Friedrich;M. Rapp
回顾了有关低电离层（D 区和 E 区）的当前知识，重点是经验结果的新方面。首先概述实验技术和相应的数据库，包括该高度范围的带电成分和最相关的中性成分，讨论电离层变化的规律（例如昼夜和季节）和不规则变化（例如由一氧化氮的变化驱动）。然后，我们转向低电离层中的“新参与者”，即带电气溶胶颗粒，例如夜光云中的中层冰颗粒或极地中层夏季回声以及源自烧蚀流星物质的流星烟雾颗粒。近年来，这些物种受到了相当大的关注，部分原因是推测对其特性的观测可能有助于检测气候变化信号。对有关这些物种的现有实验数据库进行了审查，我们表明现在有令人信服的证据表明这些非常重的电荷载流子在整个电离层下部无处不在。虽然有关这些带电物质的许多基本细节尚未完全了解，但这强调了在综合处理较低电离层电荷平衡和相关现象时，带电气溶胶颗粒不能被忽视。最后，我们对未来的研究提出建议。
Current knowledge concerning the lower ionosphere (D- and E-region) is reviewed with an emphasis on new aspects of empirical results. Starting with an overview of experimental techniques and corresponding data bases, both regarding charged as well as the most relevant neutral constituents of this altitude range, the ionospheric variability is discussed both concerning regular (e.g. diurnal and seasonal) as well as irregular variations (e.g. driven by the variability of nitric oxide). We then turn to ‘new players’ in the lower ionosphere, i.e. charged aerosol particles such as mesospheric ice particles in noctilucent clouds or polar mesospheric summer echoes and meteor smoke particles originating from ablated meteoric matter. These species have received considerable attention in recent years, in part because it is speculated that observations of their properties might be useful for the detection of climate change signals. The available experimental data base regarding these species is reviewed and we show that there is now compelling evidence for the ubiquitous presence of these very heavy charge carriers throughout the lower ionosphere. While many fundamental details regarding these charged species are not yet completely understood, this emphasizes that charged aerosol particles may not be neglected in a comprehensive treatment of the lower ionospheric charge balance and related phenomena. Finally, we close with suggestions for future research.