Influence of meteors on the mesosphere studied by the cooperative radar/lidar

雷达/激光雷达协同研究流星对中间层的影响

基本信息

批准号：
08454137
负责人：
TSUDA Toshitaka
金额：
$ 4.86万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08454137/
关键词：
Mesopause Meteor Meteor Radar Sodium Lidar Airglow Middle and Upper Atmosphere Metallic Atom Layer Sporadic Sodium Layer 大気発光層ナトリウム層リモートセンシング中層大気

项目摘要

In this study, meteor trails have been observed by the MU radar of Kyoto University, in order to investigate meteor flux and mesospheric dynamical parameters. Simultaneous lidar and airglow imager observations have been carried out and results are compared, in order to clarify the mechanism of variations of constituents in the mesosphere and mesopause region. Especially, sporadic sodium layer is focused as one of the main targets. From plenty of simultaneous observations, the following findings have been revealed.1. The meteor flux was not influenced by the major meteor stream activity, from the MU radar observation with a high sensitivity. However, if height, direction, or meteor echo strength is limited there could be a significant temporal variation.2. The temporal variation of sodium density around the mesopause with slow downward progression with a period larger than several hours was confirmed to be inertia gravity waves.3. The sporadic sodium layer was sometimes accompanied by localized temperature increase or wind shear. Especially, there was a strong correlation between the vertical shear of horizontal wind and occurrence of sporadic sodium layers. No significant correlation was found between the meteor flux and sporadic sodium layer.4. During the cooperative observation of sodium lidar and airglow imager, atmospheric gravity events were frequently observed in the airglow layer by the imagers, which have clarified climatologies and structures of small scale gravity waves in the mesopause region.5. Strong activity of bright Leonid meteors (fireballs) were observed by the MU radar about one day prior to the predicted meteor storm in November 1998. However, no significant influence on the mesopause region was found by the optical measurement.

在这项研究中，京都大学的MU雷达观察到了流星径，以研究流星通量和中层动力学参数。已经进行了同时的LiDAR和气球成像仪观测值并进行了比较，以阐明中层和间膜区域中成分变化的机理。特别是，零星的钠层是主要目标之一。从大量同时观察中，已经揭示了以下发现。1。流星通量不会受到高灵敏度的MU雷达观察的主要流星流活性的影响。但是，如果高度，方向或流星回声强度受到限制，则可能会有显着的时间变化。2。在间座周围的钠密度随着时间的下降缓慢而大于几个小时，钠密度的时间变化是惯性重力波。3。零星的钠层有时会伴随着局部温度升高或风剪。特别是，水平风的垂直剪切与零星钠层的发生之间存在很强的相关性。流星通量和零星钠层之间未发现显着相关。4。在对钠激光钠和气球成像仪的合作观察过程中，成像仪在空气表层中经常观察到大气重力事件，这已经阐明了中间区域中小规模重力波的气候和结构。5。在1998年11月预测的流星风暴之前的一天，MU雷达观察到明亮的Leonid流星（火球）的强大活性。但是，光学测量没有发现对中间区域的显着影响。