Planetary wave signatures in the equatorial atmosphere–ionosphere system, and mesosphere- E- and F-region coupling

• Published in: Journal of atmospheric and solar-terrestrial physics Vol. 68; no. 3; pp. 509 - 522
• Main Authors: Abdu, M.A., Ramkumar, T.K., Batista, I.S., Brum, C.G.M., Takahashi, H., Reinisch, B.W., Sobral, J.H.A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2006; Elsevier
• Subjects: Earth, ocean, space; Equatorial electrojet; Equatorial ionosphere; Equatorial spread F; Exact sciences and technology; External geophysics; MF radar winds; Physics of the high neutral atmosphere; Physics of the ionosphere; Physics of the magnetosphere; Planetary wave effects; Pre-reversal vertical drift; Brazil; ASW, Brazil; Equatorial spread F; Pre-reversal vertical drift; MF radar winds; Equatorial ionosphere; Equatorial electrojet; Planetary wave effects; South America; Plasma; Plasma density depression; Ionospheric sounding; Thermosphere; Energy transport; tropical zone; Mesosphere; coupling; Vertical drift; winds; Planetary scale; Height; Planetary wave; Day to day variation; Gravity; Large scale structure; Electrostatic wave; Radiowave propagation; Ionospheric E region; Ionospheric F region; Airglow; electrical field; intensity; tidal waves; Tide effect; Gravity wave; Spread F; electrical currents
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2005.03.019

Upward transport of wave energy and momentum due to gravity, tidal and planetary waves from below and extra-tropics controls the phenomenology of the equatorial atmosphere–ionosphere system. An important aspect of this phenomenology is the development of small- and large-scale structures including thin layers in the mesosphere and E-region, and the formation of wide spectrum plasma structures of the equatorial F-region, widely known as equatorial spread F/plasma bubble irregularities (that are known to have significant impact on space application systems based on trans-ionospheric radio waves propagation). It seems that the effects of tidal and gravity waves at mesospheric and thermospheric heights and their control of ionospheric densities, electric fields and currents are relatively better known than are the effects originating from vertical coupling due to planetary waves. Results from airglow, radar and ionospheric sounding observations demonstrate the existence of significant planetary wave influence on plasma parameters at E- and F-region heights over equatorial latitudes. We present and discuss here some results showing planetary wave oscillations in concurrent mesospheric winds and equatorial electrojet intensity variations in the Indian sector as well as in the mesospheric airglow and F-layer height variation in Brazil. Also presented are evidences of planetary wave-scale oscillations in equatorial evening pre-reversal electric field (F-region vertical drift) and their effects on equatorial spread F /plasma bubble irregularity development and day-to-day variability.