"Ionosph\u00E8re" . . . . . . . . . "Actes de congr\u00E8s" . "Atmosphere, Upper -- Polar regions -- Observations -- Congresses" . "1989" . "Haute atmosph\u00E8re -- R\u00E9gions polaires -- Observations" . "Magnetosphere -- Congresses" . . "Magn\u00E9tosph\u00E8re -- R\u00E9gions polaires" . "Atmosphere, Upper -- Congresses" . "Magnetosphere -- Polar regions -- Congresses" . "Magn\u00E9tosph\u00E8re" . "Polar ionosphere -- Observations -- Congresses" . "Proceedings of the NIPR Symposium on Upper Atmosphere Physics" . "Haute atmosph\u00E8re" . "Ionosphere -- Congresses" . "Proceedings of the NIPR Symposium on Upper Atmosphere Physics" . "Ionosph\u00E8re polaire -- Observations" . . . "Text" . . .