Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet
Simultaneous observations at different altitudes of ionospheric backscatter in the eastward electrojet
复制标题
东向电喷流电离层后向散射不同高度的同时观测
DOI：
10.1007/s00585-997-0055-9
复制
发表时间：
1997
影响因子：
1.9
通讯作者：
M. Lester
中科院分区：
文献类型：
--
作者：
S. Milan;M. Lester
一个共同的特点，晚上近距离的电离层后向散射的CUTLASS冰岛雷达视野是两个平行的，大约L-壳层对齐的区域向西流动，这是由于在极光向东的电离层电喷流区域的不规则性。这些反向散射通道的距离大约为100-200公里。CUTLASS冰岛雷达波束的方向和气流的纬向排列性质允许在不需要双基地测量的情况下近似确定气流角。两个流动通道具有不同的流速和谱宽度的方位角变化。两个区域中较近的一个有两个不同的光谱特征。东边的电子束探测到的频谱速度在离子声速或接近离子声速时饱和，并且频谱宽度较低（小于100 ms −1），而西边的电子束探测到的速度较低，频谱宽度较高（大于200 ms −1）。两个通道中距离较远的通道只有一个频谱特征，其速度高于离子声速，频谱宽度较高。后向散射的光谱特性与较近通道中的E区散射和较远通道中的上E区或F区散射一致。这两个通道的特性的时间变化支持目前的理论E区湍流加热和以前的观测速度依赖的后向散射截面。在未来，这种性质的观察将提供一个强大的工具，同时E-和F-区域的不规则性产生类似的（近共位或磁共轭）电场条件下的调查。
A common feature of evening near-range ionospheric backscatter in the CUTLASS Iceland radar field of view is two parallel, approximately L-shell-aligned regions of westward flow which are attributed to irregularities in the auroral eastward electrojet region of the ionosphere. These backscatter channels are separated by approximately 100–200 km in range. The orientation of the CUTLASS Iceland radar beams and the zonally aligned nature of the flow allows an approximate determination of flow angle to be made without the necessity of bistatic measurements. The two flow channels have different azimuthal variations in flow velocity and spectral width. The nearer of the two regions has two distinct spectral signatures. The eastern beams detect spectra with velocities which saturate at or near the ion-acoustic speed, and have low spectral widths (less than 100ms−1), while the western beams detect lower velocities and higher spectral widths (above 200ms−1). The more distant of the two channels has only one spectral signature with velocities above the ionacoustic speed and high spectral widths. The spectral characteristics of the backscatter are consistent with E-region scatter in the nearer channel and upper-E-region or F-region scatter in the further channel. Temporal variations in the characteristics of both channels support current theories of E-region turbulent heating and previous observations of velocity-dependent backscatter cross-section. In future, observations of this nature will provide a powerful tool for the investigation of simultaneous E- and F-region irregularity generation under similar (nearly co-located or magnetically conjugate) electric field conditions.
来自北海道 SuperDARN 雷达的初始反向散射发生统计
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
Hosokawa;K.;Nishitani;N.;et. al.
通讯作者：
et. al.