Maekawa, YasuyukiFukao, ShoichiroYamamoto, MamoruYamanaka, Manabu D.Tsuda, ToshitakaKato, SusumuWoodman Pollitt, Ronald Francisco2018-07-062018-07-061993-10Maekawa, Y., Fukao, S., Yamamoto, M., Yamanaka, M. D., Tsuda, T., Kato, S., & Woodman, R. F. (1993). First observation of the upper stratospheric vertical wind velocities using the Jicamarca VHF radar.==$Geophysical Research Letter, 20$==(20), 2235-2238. https://doi.org/10.1029/93GL02606index-oti2018http://hdl.handle.net/20.500.12816/1763The Jicamarca VHF radar (50 MHz) has detected atmospheric echoes in the so-called "gap region" from 30 to 60 km heights. These echoes are, for the first time, discriminated from clutter echoes, using both co-polarized ( co-pol) and cross-polarized (x­pol) arrays to monitor the clutter component which may enter the antenna sidelobes. The atmospheric scatterings in this region are shown to be composed of refractivity layers with thickness as of 1-2 km as in other middle atmospheric height ranges, suggesting that these scatterings are caused by thin turbulent layers. The height profile of infcrred vertical wind velocities indicates a wavy structure. The wave amplitude, as a whole, increases with height, suggesting the activity of upward-propagating gravity waves.application/pdfenginfo:eu-repo/semantics/restrictedAccessGravity waveMiddle atmosphereUpward propagating waveVHF radarinfo:eu-repo/semantics/articlehttp://purl.org/pe-repo/ocde/ford#1.05.01Geophysical Research Lettershttps://doi.org/10.1029/93GL02606