Collaborative Research: Jicamarca Radar Studies of Gravity Waves from D Region to Lower F Region

合作研究：Jicamarca 雷达对 D 区到下 F 区重力波的研究

• 批准号: 1143523
• 负责人: Erhan Kudeki
• 金额: $ 25.5万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1143523&HistoricalAwards=false
• 关键词: Collaborative; Research; Jicamarca; Radar; Studies

The work will use the 50 MHz radar at Jicamarca, Peru to observe high-frequency gravity waves in the equatorial mesosphere and lower thermosphere from about 60 to 170 km. The radar will be used in an extension of an existing MST-ISR mode. Besides transmitting long and coded pulses for interlaced detection of mesospheric echoes and ionospheric incoherent scatter radar returns (so-called MST and ISR signals), short and uncoded pulses will be transmitted to probe the turbulent equatorial electrojet height region (E-region proper) with high temporal and spatial resolution. Short-pulse data from the electrojet will be used to provide gravity wave signatures from the equatorial E region to complement the D-region and upper E-region (above 140 km) gravity wave data acquired in the MST-ISR mode. The overall objective will be to improve the current understanding of gravity wave propagation and guiding in the equatorial mesosphere and lower thermosphere and the role of gravity waves in the structuring of the region via neutral and plasma instability processes. Gravity waves are known to play a crucial role in the dynamic coupling of atmospheric regions. Waves that propagate upward through the mesosphere and lower thermosphere (or that may be generated as secondary waves) may grow to significant amplitudes in the E and F regions of the ionosphere. The fast continuous sampling by the Jicamarca radar provides important information on short period (5-15 minute) gravity wave oscillations and instabilities of the neutral atmosphere at low latitudes. Short period waves are always present in the equatorial mesosphere as evident in Jicamarca vertical wind data and also in the equatorial upper E-region as evident in enhanced backscatter from the 150-km altitude region observed at Jicamarca. The connection of these wave systems and their relation to gravity waves in the intervening E-region altitudes remain unknown and unexplored. Above Jicamarca, this region is occupied by a turbulent equatorial electrojet (EEJ) causing strong radar backscatter. The modulation of this backscatter signal is what will be exploited for a novel study of the gravity wave content of the region and its relationship to gravity waves observed in the mesosphere and the upper E-region.

这项工作将使用位于秘鲁Jicamarca的50兆赫雷达，在大约60至170公里的赤道中间层和低层热层观测高频重力波。该雷达将用于现有MST-ISR模式的扩展。除了发射编码的长脉冲用于交错探测中间层回波和电离层非相干散射雷达回波（MST和ISR信号）外，还将发射编码的短脉冲用于探测湍流赤道电喷高度区（e区固有），具有较高的时空分辨率。来自电射流的短脉冲数据将用于提供赤道E区重力波特征，以补充MST-ISR模式获得的d区和上E区（140公里以上）重力波数据。总体目标将是改善目前对重力波在赤道中间层和下层热层中的传播和引导的理解，以及重力波通过中性和等离子体不稳定过程在该地区结构中的作用。众所周知，重力波在大气区域的动态耦合中起着至关重要的作用。通过中间层和下层热层向上传播的波（或可能作为次级波产生的波）可能在电离层的E和F区增长到显著的振幅。Jicamarca雷达的快速连续采样提供了关于低纬度中性大气短周期（5-15分钟）重力波振荡和不稳定性的重要信息。短周期波总是存在于赤道中间层，这在Jicamarca垂直风资料中得到了证明，在Jicamarca观测到的150 km高度区域增强的后向散射中也得到了证明。这些波系之间的联系以及它们与介入性e区高度的重力波之间的关系仍然是未知和未探索的。在Jicamarca上方，这一区域被湍流赤道电喷流（EEJ）占据，造成强烈的雷达反向散射。这种后向散射信号的调制将被用于研究该区域的重力波含量及其与中间层和上部e区观测到的重力波的关系。