Three-dimensional imaging of atmospheric waves in the thermosphere using network observations over Japan

1)在本研究期间，自2000年7月起在佐田（鹿儿岛）和自2001年10月起在达尔文（澳大利亚）开始了气辉图像的常规观测。这四个台站与陆别（北海道）和志贺（Siga）（自1998年10月起）一起继续拍摄气辉图像。在冲绳（1999年8月）和种子岛（2002年8月）进行了战役观察。自2000年10月以来，法布里-珀罗干涉仪在Shigaraki测量中间层和热层风。这些常规测量的快速绘图可在http：//stdb2.stelab.nagoya-u.ac.jp/omti/2）中层顶区域重力波的结果：a）重力波的气候学（发生、传播方向等）是从日本和澳大利亚台站的气辉图像的统计研究中获得的。B）在中层顶区发现了定域（孤立）结构。我们认为，非线性波-波相互作用造成这种结构。c）gr的高度 关于我们 3）中尺度电离层移动扰动（MSTID）的研究结果：a）通过对日本的气辉图像进行统计研究，获得了MSTID的气候特征（发生、波长、传播方向等）。B）基于卫星数据和包括FPI背景风信息在内的模型计算的比较，我们表明MSTID不是由重力波直接引起的，而是对应于某些电离层不稳定性产生的电场结构。（3）基于日本和澳大利亚的同步气辉成像观测，我们发现这种电场结构沿两半球间的磁场线沿着传播。（4）大尺度电离层扰动（LSTID）的结果：磁暴期间LSTID被识别为630 nm的气辉增强。我们表明，模式计算和直接风测量的基础上，这LSTID是由极向风增强（传播赤道）在热层。我们还从观测到的极光区能量输入论证了简单的极光区风生成模型不能解释观测到的LSTID特征。5）基于日本和澳大利亚的同步气辉成像观测，我们发现了两半球之间对称的等离子体泡结构。6）在研究期间，我们在日本北方（北海道）成功地观测了11次低纬度极光。7）根据FPI和MU雷达对中层风的同时观测，估算了气辉发射高度的时间变化。少

1) Routine observation of airglow image has been started since July 2000 at Sata (Kagoshima) and since October 2001 at Darwin (Australia) during this research period. Together with Rikubetsu (Hokkaido) and Shigaraki (Siga) (since October 1998), these four stations continue taking airglow images. Campaign observations were carried out at Okinawa (August, 1999) and Tanegashima (August 2002). A Fabry-Perot interferometer (FPI) measures mesospheric and thermospheric wind since October 2000 at Shigaraki. Quick-look plots of these routine measurements are available at http://stdb2.stelab.nagoya-u.ac.jp/omti/.2) Results for gravity waves in the mesopause region : a) Climatology (occurrence, propagation directions, and so on) of gravity waves were obtained from statistical study of airglow images at these Japanese and Australian stations. b) Localized (isolated) structure was found in the mesopause region. We suggest that nonlinear wave-wave interactions caused this structure. c) Heights of gr … More avity waves and airglow emissions were determined by a triangulation technique using airglow images obtained at two nearby sites.3) Results for medium-scale traveling ionospheric disturbance (MSTID) : a) Climatology (occurrence, wavelength, propagation directions, and so on) of MSTIDs were obtained from statistical study of airglow images in Japan. b) Based on a comparison of satellite data and model calculations including background wind information from FPI, we show that the MSTIDs are not directly caused by gravity waves, but correspond to the electric field structure generated by some ionospheric instability. c) Based on simultaneous airglow imaging observations in Japan and Australia, we found that this electric field structure propagates along magnetic field line between the two hemispheres.4) Results for large-scale traveling ionospheric disturbance (LSTID) : LSTIDs were identified as 630-nm airglow enhancement during magnetic storms. We showed on the basis of model calculations and direct wind measurements that this LSTID was caused by poleward wind enhancement (propagating equatorward) in the thermosphere. We also argued from the observed auroral zone energy input that simple wind generation model in the auroral zone did not explain the observed LSTID features.5) Based on the simultaneous airglow imaging observations in Japan and Australia, we found symmetric plasma bubble structures between the two hemispheres.6) During the research period, we have succeeded observations of low-latitude aurora 11 times in the northern part of Japan (Hokkaido). Two of them were observed in the mainland of Japan (Shigaraki), making a record of lowest latitude of auroral measurement in Japan.7) From simultaneous measurement of mesospheric wind by the FPI and the MU radar, temporal variations of airglow emission height were estimated. Less