Collaborative observations of atmospheric waves and constituent variations in the MLT region using ground-based observation network in Japan and America with satellite observations.

本项目的目标是通过日本、美国和巴西的地面无线电和光学观测以及卫星观测，澄清中间层低热层（MLT）区域各种空间和时间尺度的变化，特别是大气波的变化和相关成分的变化。揭示了大气重力波与气辉辐射廓线变化的关系。已经开发了一个新的OH全天空成像仪，并在美国科罗拉多与一个钠激光雷达和两个成像仪进行了协调观测（CO2成像仪活动）。通过对日本、美国和巴西等地的气辉成像观测和射线追踪，阐明了气辉图像中的涟漪结构与大气稳定度之间的关系，发现了MLT区热带扰动与重力波之间的联系。利用雷达、卫星观测和GCM模式研究了非迁移潮，提出了气辉图像特征的纬向变化。通过三维模拟，弄清了气辉中的破碎重力波和涟漪结构。如上所述，本项目的成果不仅限于协调观测的简单输出，还将扩展到更广泛的研究区域，这将进一步促进日本、美国和巴西之间在高层大气区域的合作。

The goal of this project is to clarify various spatial and temporal scales of variations, especially variations of atmospheric waves and associated constituent variations, in the mesosphere lower thermosphere (MLT) region by ground-based using radio and optical observation in the Japan, USA and Brazil as well as satellite observations.From coordinated observations at Shigaraki MU radar site, relations between atmospheric gravity waves and variations of airglow emission profiles have been revealed. A new OH all-sky imager has been developed and coordinated observations with a sodium lidar and two imagers have been carried out (CO2 imager campaign) in Colorado, USA. Relations between ripple structures in the airglow image and atmospheric stability have been clarified.Associations between troposheric disturbance and gravity waves in the MLT region have been found by observations and ray-tracing using airglow imaging observations in Japan, USA and Brazil. Effect of atmospheric tides are also discussed.Non-migrating tides has been studied using radar, satellite observations and a GCM model, and zonal variability of airglow image characteristics has been suggested. Three-dimensional simulation has clarified breaking gravity waves and ripple structures in the airglow.As mentioned above, the results of this project is not limited to the simple output of coordinated observations and spread over a wider research region, which would further stimulate future collaboration between Japan, USA and Brazil in the upper atmosphere region.