Mostrar el registro sencillo del ítem Yamamoto, Mamoru Fukao, Shoichiro Woodman Pollitt, Ronald Francisco Ogawa, Tadahiko Tsuda, Toshitaka Kato, Susumu 2018-07-06T19:32:54Z 2018-07-06T19:32:54Z 1991-09
dc.identifier.citation Yamamoto, M., Fukao, S., Woodman, R. F., Ogawa, T., Tsuda, T., & Kato, S. (1991). Mid‐latitude E region field‐aligned irregularities observed with the MU radar.==$Journal of Geophysical Research: Space Physics, 96$==(A9), 15943-15949. es_ES
dc.identifier.govdoc index-oti2018
dc.description.abstract Fine structures E region field-aligned irregularities were observed on June 24–25, 1989, with the MU radar at Shigaraki, Japan (34.9N, 136.1E; geomagnetic latitude 25.0N). The 3.2-m scale irregularities were observed with the MU radar in five main beam directions, each of which was nearly perpendicular to the geomagnetic field at 100 km altitude. Doppler spectra were obtained every 20 s with a range resolution of 600 m. Field-perpendicular echoes appeared from 2130 to 2330 LT and from 0400 to 1100 LT, times that correspond to postsunset and postsunrise period in the E region. A preliminary examination of the Doppler spectra indicates spectral widths of 50–120 m s−1 and the mean Doppler velocities are well below the ion acoustic speed. These spectral characteristics are consistent with those obtained in the equatorial and auroral electrojets, and have been attributed to the gradient drift instability. The echoes observed during the postsunset and postsunrise periods showed quite different morphologies in the time-height distribution. For this reason, they are classified into two types, ‘continuous’ and ‘quasi-periodic.’ The appearance of the ‘continuous’ echoes was mainly continuous in time and situated between 90 and 100 km altitude during the postsunrise period. The appearance of the ‘quasi-periodic’ echoes was intermittent with periods of 5–10 min and situated above 100 km altitude during the postsunset period. The quasi-periodic echoes showed phase propagation toward the radar, while the averaged mean Doppler velocity was away from the radar. By measuring the time delays in echo regions from five directions, an apparent westward motion (approximately 120 m s−1) of the irregularity regions was estimated. es_ES
dc.format application/pdf es_ES
dc.language.iso eng es_ES
dc.publisher American Geophysical Union es_ES
dc.relation.ispartof urn:issn:2169-9380
dc.rights info:eu-repo/semantics/restrictedAccess es_ES
dc.subject E Region es_ES
dc.subject Magnetic fields es_ES
dc.subject Radar es_ES
dc.subject Geomagnetism es_ES
dc.subject Echoes es_ES
dc.subject Doppler effect es_ES
dc.title Mid‐latitude E region field‐aligned irregularities observed with the MU radar es_ES
dc.type info:eu-repo/semantics/article es_ES
dc.subject.ocde es_ES
dc.identifier.journal Journal of Geophysical Research: Space Physics es_ES
dc.description.peer-review Por pares es_ES
dc.identifier.doi es_ES




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