Results 11 to 20 of about 11,557,211 (324)
Geomagnetic storm and equatorial spread-F [PDF]
Annales Geophysicae, 2004 In August 2000, a new ionospheric sounding station was established at Sao Jose dos Campos (23.2° S, 45.9° W; dip latitude 17.6° S), Brazil, by the University of Vale do Paraiba (UNIVAP). Another ionospheric sounding station was established
F. Becker-Guedes +6 more
doaj +8 more sources
Spread F – an old equatorial aeronomy problem finally resolved? [PDF]
Annales Geophysicae, 2009 One of the oldest scientific topics in Equatorial Aeronomy is related to Spread-F. It includes all our efforts to understand the physical mechanisms responsible for the existence of ionospheric F-region irregularities, the spread of the traces in a ...
R. F. Woodman
doaj +6 more sources
On the Dynamics of Equatorial Spread F [PDF]
Australian Journal of Physics, 1974 A theory is proposed to explain the occurrence of spread F in the equatorial ionosphere. It is envisaged as a multistage process involving: movement of ionization drift with atmospheric gravity waves that results in spatial resonance, consequent ...
Tom Beer
openaire +2 more sources
HF radar observations of equatorial spread-F over West Africa [PDF]
Annales Geophysicae, 1996 New experimental data depicting equatorial spread-F were taken during an HF radar sounding campaign in Korhogo (Ivory Coast, 9°24N, 5°37W, dip 4°S). Range-time-intensity maps of the radar echoes have been analyzed to identify the signatures of density
J.-F. Cécile, P. Vila, E. Blanc
doaj +2 more sources
Nocturnal and seasonal variations of equatorial spread-F
Journal of Atmospheric and Terrestrial Physics, 1961 A new classification of spread-F echo patterns based on the relative amplitudes of the echoes is described and discussed. The results of nocturnal and seasonal variations in spread-F at Waltair are presented and a comparison is made with data of other equatorial stations with particular reference to that of Kodaikanal.
M.S.V.Gopal Rao, B.Ramachandra Rao
openaire +2 more sources
Upwelling: a unit of disturbance in equatorial spread F [PDF]
Progress in Earth and Planetary Science, 2015 Plasma structure in the nighttime equatorial F layer, often referred to as equatorial spread F (ESF), is not uniformly distributed, either in time or in space.
R. Tsunoda
semanticscholar +2 more sources
Gravity wave initiation of equatorial spread F/plasma bubble irregularities based on observational data from the SpreadFEx campaign [PDF]
Annales Geophysicae, 2009 The data from ground based experiments conducted during the 2005 SpreadFEx campaign in Brazil are used, with the help of theoretical model calculations, to investigate the precursor conditions, and especially, the role of gravity waves, in the ...
M. A. Abdu +5 more
doaj +2 more sources
Generation of large-scale equatorial F-region plasma depletions during lowrange spread-F season [PDF]
Annales Geophysicae, 2004 All-sky imaging observations of the F-region OI 630nm nightglow emission allow us to visualize large-scale equatorial plasma depletions, generally known as trans-equatorial plasma bubbles. Strong range type spread-F is the radio signature of these
Y. Sahai +6 more
doaj +3 more sources
Effect of equatorial ionization anomaly on the occurrence of spread-F [PDF]
Annales Geophysicae, 1997 The unique geometry of the geomagnetic field lines over the equatorial ionosphere coupled with the E-W electric field causes the equatorial ionization anomaly (EIA) and equatorial spread-F (ESF).
P. T. Jayachandran +3 more
doaj +4 more sources
HF radar observations of equatorial spread-F over West Africa
Annales GeophysicaeNew experimental data depicting equatorial spread-F were taken during an HF radar sounding campaign in Korhogo (Ivory Coast, 9°24N, 5°37W, dip 4°S). Range-time-intensity maps of the radar echoes have been analyzed to identify the signatures of density ...
J.-F. Cécile, P. Vila, E. Blanc
doaj +1 more source