Study of interaction between neutral and ionized atmosphere through field-aligned

根据我们以前的研究，我们预计电离层F区和E区的场向不规则(FAI)分别与Perkins不稳定性和梯度漂移不稳定性有关。然而，对于它们复杂的生成过程和空间结构的原因，我们还远远不了解。利用这笔科研补助，我们在日本和国外开展了多次观测活动，揭示了中性大气和电离大气之间的耦合过程，并在国际著名期刊上发表了40篇论文。以下是我们在这项拨款下进行的研究1.我们开发了一台31.57 MHz的新雷达，用于观测E区FAI和流星回波。我们可以用E区FAI回波同时测量中性风。该雷达于2000年在MU雷达站建成，并用于长期实验。我们可以找到FAI回波的准确频率出现及其与中性风的相关性。E区FAI研究：我们使用福井通信研究实验室的FM-CW雷达，与MU雷达同步获取电离图。在美国，与SRI国际一起对准周期回波进行了雷达观测。开展了二维计算机模拟，研究了极化电场的产生。F区FAI研究：我们参与了西太平洋行动(从台湾到印度尼西亚的电离层探空网)，并在菲律宾宿务操作了FM-CW雷达。我们利用MU雷达、气辉成像仪和GPS接收器开展了研究F区电离层和FAI的前沿活动。随着印度尼西亚赤道大气雷达的建成，我们在南部低纬地区进行了第一次FAI观测。通过这些观测，我们研究了F区FAI及其与背景大气的关系。

From our previous studies we expect that field-aligned irregularities (FAI) in the ionospheric F- and E-regions are associated with the Perkins instability and the gradient-drift-instability, respectively. However we are still far from the understanding of their complicated generating processes and reason of spatial structures. With this grant-in-aid for scientific research, we conducted number of observation campaigns in Japan and abroad to reveal coupling processes between neutral and ionized atmosphere, and published 40 papers to famous international journals. Following is the list of studies we conducted under this grant.1. We developed a new radar of 31.57 MHz for observing E-region FAI and meteor echoes. We can measure neutral winds simultaneously with the E-region FAI echoes. The radar was completed in the MU radar site in 2000, and used for long-term experiment. We could find accurate frequency occurrence of the FAI echoes, and its correlation with the neutral winds.2. Study of E-region FAI : We operated the FM-CW radar of Communication Research Laboratory in Fukui obtain ionogram simultaneously with the MU radar. In USA radar observations of Quasi-Periodic echoes were conducted with SRI International. We developed two dimensional computer simulation, and studied generation of polarization electric field.3. Study of F-region FAI : We participated in the WestPac campaign (network of ionosondes from Taiwan to Indonesia), and operated the FM-CW radar in Cebu, Philippines. We conducted the FRONT campaign to study F-region ionosphere and FAI with the MU radar, airglow imagers and GPS receivers. With the Equatorial Atmosphere Radar completed in Indonesia, we conducted the first observations of FAI in the southern low-latitude region. Through these observations we studied F-region FAI and its relationship to the background atmosphere.