This study extends the investigation of quasi-periodic ripples in the F-region electron content reported by Birch and Hargreaves (2020a) to determine their flow velocity and wavelength, using data from the EISCAT Svalbard radars (the 42m antenna being field-aligned and the 32m scanning in a circular pattern at a fixed angle from the field). The ripples were extracted from the 42m electron content between altitudes 213 and 389 km in the noon and midnight sectors using a bandpass filter which reduces the noise component while removing long-term trends. These ripples were found to have an average periodicity of about 21 min in the noon sector and 27 min at night. Using the 32m line-of-sight velocity data, they were also found to propagate in the noon sector at about 467 m/s in a westerly direction with a wavelength of 581 km, and in the night sector at about 283 m/s in a southerly direction with a wavelength of 454 km. The directions compare favourably with modelled plasma flows from the SuperDARN network of coherent scatter radars.

这项研究扩展了Birch和Hargreaves（2020a）报告的F区电子含量中的准周期波动的研究，以确定其流速和波长，使用了EISCAT斯瓦尔巴德雷达的数据（42m天线进行了场对准并且以距地面固定角度的圆形图案扫描32m）。使用带通滤波器从中午和午夜区域海拔213和389 km之间的42m电子含量中提取了纹波，该滤波器可减少噪声分量，同时消除长期趋势。发现这些涟漪在中午时段平均周期约为21分钟，在夜间为27分钟。使用32m的视线速度数据，还发现它们在正午扇区以约467 m / s的速度向西传播，传播波长为581 km，在夜区，向南约283 m / s，波长454 km。这些方向与相干散射雷达的SuperDARN网络建模的等离子体流相比具有优势。