低热层金属层及其与电离层E层耦合研究

近年来，国际上对于金属层的激光雷达探测中，一个非常有意义的现象是所谓"金属层向低热层拓展（或者低热层金属层）"现象。同时，也伴生了一系列相关的科学问题，例如，低热层金属层的源是什么？低热层钠层的分布是否存在纬度差异或者东西半球差异？如果有，那么这种分布差异与流星注入、Es、大气动力学（波动）是否有关？项目从以上问题出发，通过多站点钠激光雷达的长期钠层探测资料，结合共体的电离层探测手段及卫星掩星探测资料，分析低热层钠层在不同纬度、东西半球分布的时空特性，以及与电离层Es、流星注入、大气波动之间的内在联系，试图理解低热层钠层的长期变化规律，探索其形成的机制和可能源区。

Recently, in the mesospheric and lower thermospheric (MLT) region, a new topic about the metal layers is the "thermospheric enhaced metal layer",which is deemed as a high-altitude extension of the neutral metal layer. However, the new scientific problems are also arised, e.g., what is the source of the thermospheric enhanced metal layer? Are there general principles and features of the thermospheric enhanced metal layers? What atmosphere dynamics structure do the thermospheric enhanced metal layers reveal? What's the relationship between the thermospheric enhanced metal layers and Es, meteors? We will use the sodium lidars of different latitudes and longitudes to detect the thermospheric enhaced sodium layers. With the help of the common volume observations from the radio equipments (ionosondes, meteor radars) as well as the satellite observations, we will focus on the following topics: (1) Statistic of thermospheric enhanced metal (sodium) layers in existing data, study the distribution of them (both in latitude and longntude, time); The comparison of features between thermospheric enhanced sodium layers in the Eastern and Western Hemisphere (e.g. Beijing & Boulder) and corresponding mechanisms; (2) Analyzing the downward (or upward) phase progression to figure out whether the thermospheric enhanced sodium layers are transported or produced locally; the relationship between ions layers and thermospheric enhanced sodium layers; (3) Relationship between thermospheric enhanced sodium layer and simultaneous sporadic metal layer, as well as the relationship between the thermospheric enhanced sodium layer and Es, meteor input.