Evidence of meso-scale structure in the high-latitude thermosphere

• Published in: Annales Geophysicae
• Main Authors: A. L. Aruliah, E. Griffin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2001
• Subjects: Science; Q; Physics; QC1-999; Geophysics. Cosmic physics; QC801-809; EISCAT
• Online Access: https://doi.org/10.5194/angeo-19-37-2001; https://doaj.org/article/55d68b51a9f34b1aa7bef1c35761de82

There is a widely held assumption that the thermospheric neutral gas is slow to respond to magnetospheric forcing owing to its large inertia and therefore, may be treated as a steady state background medium for the more dynamic ionosphere. This is shown to be over simplistic. The data presented here compare direct measurements of the thermospheric neutral winds made in Northern Scandinavia by Fabry-Perot Interferometers (FPIs) with direct measurements of the ionosphere made by the EISCAT radar and with model simulations. These comparisons will show that the neutral atmosphere is capable of responding to ionospheric changes on mesoscale levels, i.e., spatial and temporal scale sizes of less than a few hundred kilometres and tens of minutes, respectively. Key words. Atmospheric composition and structure (air-glow and aurora; instruments and techniques) – Ionosphere (ionosphere-atmosphere interactions)