Identification of active fossil bubbles based on coordinated VHF radar and airglow measurements

R. Sekar (1) , D. Chakrabarty (1) , S. Sarkhel (1) , A. K. Patra (2) , C. V. Devasia (3) , M. C. Kelley (4)

1 PRL - Physical Research Laboratory [Ahmedabad]
2 NARL - National Atmospheric Research Laboratory [Tirupati]
3 Space Physics Laboratory
4 CSL - Computer Systems Lab - School of Electrical and Computer Engineering - Cornell University

Plasma irregularity structures associated with an Equatorial Spread-F (ESF) event were recorded by the Indian VHF Radar on 26?27 April 2006 near midnight hours. The plasma structures were found to be isolated without having bottomside structure. They moved predominantly downward and the structures were found to be less turbulent than their post-sunset counterparts. However, the structures were characterized by meter-scale size irregularities. These structures are identified for the first time as plasma depletion structures using simultaneous, collocated measurements of OI 630.0 nm airglow intensity variations. The variation of the base height of ionospheric F layer over dip equator is also presented to buttress the result. Further, these plasma structures are shown to be "active fossil bubbles".

Domaines: Océan, Atmosphère; Sciences de la Terre

R. Sekar, D. Chakrabarty, S. Sarkhel, A. K. Patra, C. V. Devasia, et al.. Identification of active fossil bubbles based on coordinated VHF radar and airglow measurements. Annales Geophysicae, 2007, 25 (10), pp.2099-2102. ⟨hal-00318391⟩