Collaborative observations of equatorial atmosphere dynamics

本研究的主要目的是揭示赤道地区特别是印度尼西亚上空的中层大气动力学特征。我们利用雅加达的流星风雷达和蓬甸纳的中频雷达继续在中层顶区域进行长期观测。我们还在Pontianak进行了密集的无线电探空运动，以分析震源区域附近大气波的行为。短周期、小垂直尺度的风速波动具有明显的季节变化特征，且与水汽含量、平均纬向风速等背景条件有关。在印度尼西亚获得的这些数据被纳入赤道大气雷达网数据库，并与其他雷达、卫星数据和数值模式结果进行比较。较清晰地描述了低纬度日、半日潮的精确空间结构和中间层半年涛动（MSAO）的纵向依赖性。此外，正在开发利用无线电探空仪数据估计动量通量的新方法。我们还建立了一条从印度尼西亚到日本和澳大利亚的直接数据传输路线。

The main purpose of this study is to reveal the characteristics of middle atmosphere dynamics over equatorial region, especially over Indonesia. We continued long-period observations around mesopause region using Meteor Wind Radar at Jakarta and MF Radar at Pontianak. We also con-ducted an intensive radiosonde sounding campaign at Pontianak to analyze behavior of atmospheric waves near the source region. The variances of wind velocity fluctuations with short periods and small vertical scales showed clear seasonal variations, and they seemed to be correlated with background conditions such as water vapor content and mean zonal wind velocity. Those data obtained in Indonesia were included in the database of equatorial atmosphere radar network, and compared with data obtained from other radars, satellite, and results of numerical models.Precise spatial structure of diurnal and semidiurnal tides in lower latitude and longitudinal dependence of Mesospheric Semi Annual Oscillation(MSAO) were clearly described. Additionally, new methods of estimation for momentum flux using radiosonde data are under development. We also constructed a direct data transfer route via Internet from Indonesia to Japan and Australia.