First observations of detached equatorial ionospheric plasma depletions using oi 630.0 nm and oi 777.4 nm emissions nightglow ...

• Grant number: 06/02997-9
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Duration: September 01, 2006 - August 31, 2007
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: José Ricardo Abalde Guede
• Grantee: José Ricardo Abalde Guede
• Host Institution: Instituto de Pesquisa e Desenvolvimento (IP&D). Universidade do Vale do Paraíba (UNIVAP). São José dos Campos , SP, Brazil

Abstract

Near-simultaneous all-sky (180o field of view) observations of the OI 630.0 nm and OI 777.4 nm nightglow emissions are being carried out on a routine basis at “Laboratorio Nacional de Astrofisica (LNA)”, Brazópolis (22.5o S, 45.6o W; dip latitude 17.5o S; altitude 1860 m), Brazil, since September 2002. The all-sky imaging observations of the OI 630.0 nm and OI 777.4 nm emissions, which arise from the dissociative recombination of O2+ ions and radiative recombination of O+ ions (mainly), respectively, are used to monitor the morphology and dynamics of the equatorial F-region at the respective emission heights. In this paper we present and discuss the first observations showing detached equatorial F-region plasma depletions or bubbles. Three cases are presented from observations during the years 2002 and 2003. We suggest a possible mechanism for their generation. (AU)