Range‐time‐intensity (RTI) plots of 50 MHz radar backscatter detected at Jicamarca from the 150‐km region of the equatorial ionosphere exhibit necklace‐shaped multilayered structures first reported by Kudeki and Fawcett (1993, https://doi.org/10.1029/93GL01256). The backscatter layers also exhibit quasi‐periodic intensity fluctuations with periods of about 5–15 min and are separated from adjacent layers by thin and undulating regions of no detectible power returns. A study of the fluctuating backscatter layers and undulating gap regions will be presented using VIPIR ionosonde data taken at the Jicamarca Radio Observatory simultaneously with high‐resolution 50‐MHz radar backscatter data. VIPIR virtual reflection height variations in time are noted to match the RTI gap‐region undulations very closely at selected VIPIR frequencies (or, equivalently, electron densities at reflection heights). This matching enables assigning “true heights” to VIPIR virtual height contour maps, and a joint study of the contour maps with the 50‐MHz radar RTI maps strongly suggests that correlated fluctuations and undulations observed in VIPIR and 50‐MHz radar data are indicative of gravity wave‐induced variations in the 150‐km region ionosphere. Accordingly, a complete explanation of the 150‐km echo phenomenon will need to include gravity wave coupling and forcing effects in the enhancement and suppression processes that can account for the observed fluctuations and gap‐region features of necklace‐shaped 150‐km echo maps.

中文翻译：

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在Jicamarca观测到的150 km回波中的重力波签名的VIPIR和50 MHz雷达研究

在赤道电离层150公里区域的Jicamarca探测到的50 MHz雷达后向散射的时空强度（RTI）图显示了Kudeki和Fawcett（1993，https://doi.org/）首次报道的项链状多层结构。 10.1029 / 93GL01256）。背向散射层还表现出准周期性的强度波动，周期约为5-15分钟，并且通过薄薄且起伏不定的区域与相邻层隔开，没有可检测到的功率返回。将同时使用在Jicamarca无线电天文台获取的VIPIR电离探空仪数据和高分辨率50 MHz雷达反向散射数据，对波动的反向散射层和起伏的间隙区域进行研究。注意到VIPIR虚拟反射高度随时间的变化与选定VIPIR频率下的RTI间隙区域起伏非常匹配（或等效地，反射高度的电子密度）。这种匹配可以为VIPIR虚拟高度等高线图分配“真实高度”，并且对等高线图与50-MHz雷达RTI图的联合研究强烈表明，在VIPIR和50-MHz雷达数据中观察到的相关涨落和起伏表明重力波在150 km电离层区域引起的变化。因此，对150 km回波现象的完整解释将需要包括增强和抑制过程中的重力波耦合和强迫效应，这些因素可以解释项链状150 km回波图的观测到的波动和间隙区域特征。对等高线图和50 MHz雷达RTI图的联合研究有力地表明，在VIPIR和50 MHz雷达数据中观察到的相关波动和起伏表明重力波在150 km电离层中引起了变化。因此，对150 km回波现象的完整解释将需要包括增强和抑制过程中的重力波耦合和强迫效应，这些因素可以解释项链状150 km回波图的观测到的波动和间隙区域特征。对等高线图和50 MHz雷达RTI图的联合研究有力地表明，在VIPIR和50 MHz雷达数据中观察到的相关波动和起伏表明重力波在150 km电离层中引起了变化。因此，对150 km回波现象的完整解释将需要包括增强和抑制过程中的重力波耦合和强迫效应，这些因素可以解释项链状150 km回波图的观测到的波动和间隙区域特征。