Equatorial F region vertical plasma drifts: seasonal and longitudinal asymmetries in the American sector

Journal Article · Sat Nov 01 04:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA091iA11p12055· OSTI ID:6984206

Batista, I S; Abdu, M A; Bittencourt, J A

Longitudinal and seasonal asymmetries in the evening ionospheric F region plasma vertical drift (V/sub z/) enhancements, between two longitudinally separated stations situated along the magnetic equator, in the American sector, are investigated under solar maximum conditions, based on results obtained from the analysis of ionosonde data for these stations. The two stations are Huancayo, Peru, and Fortaleza, Brazil, which have markedly different magnetic declination angles. The observed asymmetries are interpreted using a detailed numerical simulation of the E and F region electrodynamic coupling process that takes into account also its asymmetry about the magnetic equator arising from the finite magnetic declination angle. The results of the simulation show, in agreement with observations, that the occurrence time of the evening F region vertical drift prereversal peak and its seasonal variation at a station are controlled by the magnetic declination angle at that station, which determines the seasonal variation of the sunset times (and hence the integrated Pedersen conductivity longitudinal gradient) at its magnetic conjugate E layers. The amplitude of the prereversal peak, on the other hand, undergoes the influence of the magnetic declination angle as well as of the thermospheric zonal wind component.

• Research Organization: Instituto de Pesquisas Espaciais, Sa-tildeo Jose dos Campos, Sa-tildeo Paulo, Brazil
• OSTI ID: 6984206
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 91:A11; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COUPLING
DATA ANALYSIS
DISTRIBUTION
E REGION
EARTH ATMOSPHERE
ELECTRODYNAMICS
F REGION
GEOMAGNETIC EQUATOR
IONOSPHERE
MATHEMATICAL MODELS
NOCTURNAL VARIATIONS
PLANETARY IONOSPHERES
PLASMA DRIFT
SEASONAL VARIATIONS
SOLAR ACTIVITY
SPATIAL DISTRIBUTION
VARIATIONS