Simultaneous OI 630 nm imaging observations of thermospheric gravity waves and associated revival of fossil depletions around midnight near the equatorial ionization anomaly (EIA) crest

Abstract ∼ 19 ° N), India, on 16 April 2012. Northward-propagating and east–west-aligned GWs (λ ∼ 210  km, v ∼ 64  m s- 1 τ ∼ 0.91  h) were seen around midnight. Persisting for ∼ 2  h, this GW activity revived two co-existing and eastward-drifting fossil depletions, DP1 and DP2. GW-driven revival was prominently seen in depletion DP1, wherein its apex height grew from ∼ 600 to > 800  km, and the level of intensity depletion increased from ∼ 17 % to 50 %. The present study is novel in the sense that simultaneous observations of thermospheric GW activity and the associated evolution of depletion in OI 630 nm airglow imaging, as well as that around local midnight, have not been reported earlier. The current understanding is that GW phase fronts aligned parallel to the geomagnetic field lines and eastward-propagating are more effective in seeding Rayleigh–Taylor (RT) instability. Here, GW fronts were east–west-aligned (i.e., perpendicular to the geomagnetic field lines) and propagated northward, yet they revived fossil depletions.

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch

References and Relationships

• Bibliographic citation: Simultaneous OI 630 nm imaging observations of thermospheric gravity waves and associated revival of fossil depletions around midnight near the equatorial ionization anomaly (EIA) crest ; volume:42 ; number:1 ; year:2024 ; pages:131-143 ; extent:13 ; Annales geophysicae ; 42, Heft 1 (2024), 131-143 (gesamt 13)

Contributors, Places and Time

• Creator: Parihar, Navin ; Padincharapad, Saranya ; Singh, Anand Kumar ; Mahavarkar, Prasanna ; Dimri, A. P.

Further information

• DOI: 10.5194/angeo-42-131-2024
• URN: urn:nbn:de:101:1-2405090418287.497027294553
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 14.08.2025, 10:59 AM CEST