Spatial structure of the E region field-aligned irregularities revealed by the MU radar


  • Mamoru Yamamoto,

  • Norio Komoda,

  • Shoichiro Fukao,

  • Roland T. Tsunoda,

  • Tadahiko Ogawa,

  • Toshitaka Tsuda


The MU radar (34.9°N, 136.1°E, geomagnetic latitude 25.0°N) is utilized to observe the spatial structures of the field-aligned irregularities in the midlatitude E region. The multibeam observation in 12 directions has found that the “quasi-periodic” echoes have a monochromatic wave structure propagating toward SSW. Much smaller-scale structure of the irregularities has been observed by the interferometry techniques with three receivers. The results are consistent with a model in which a southward propagating gravity wave modulates the sporadic E layer to generate the quasi-periodic echoes of the irregularities.