Results 21 to 30 of about 92,748 (240)
Seasonal variations of equatorial spread-F [PDF]
Annales Geophysicae, 1994 The occurrence of spread-F at Trivandrum (8.5°N, 77°E, dip 0.5°N) has been investigated on a seasonal basis in sunspot maximum and minimum years in terms of the growth rate of irregularities by the generalized collisional Rayleigh-Taylor (GRT ...
K. S. V. Subbarao, B. V. Krishna Murthy
doaj +1 more source
Earth, Planets and Space, 2023 A new mode for two dimensional observations of F-region irregularities in the magnetic equatorial plane using AMISR-14 is described. Examples of observations are presented and illustrate the ability of the system to capture the genesis, evolution, and ...
F. Rodrigues +7 more
semanticscholar +1 more source
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
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Density enhancements associated with equatorial spread F [PDF]
Annales Geophysicae, 2010 Forces governing the three-dimensional structure of equatorial spread-F (ESF) plumes are examined using the NRL SAMI3/ESF three-dimensional simulation code.
J. Krall +3 more
doaj +1 more source
Progress in Earth and Planetary Science, 2018 Typical equatorial spread-F events are often said to occur during post-sunset, equinox conditions in most longitude sectors. Recent studies, however, have found an unexpected high occurrence of ionospheric F-region irregularities during June solstice ...
Fabiano S. Rodrigues +6 more
doaj +1 more source
Multistation digisonde observations of equatorial spread F in South America [PDF]
Annales Geophysicae, 2004 Directional ionogram and F-region drift observations were conducted at seven digisonde stations in South America during the COPEX campaign from October to December 2002.
B. W. Reinisch +7 more
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Seasonal variations of equatorial spread-
Annales Geophysicae, 1994 The occurrence of spread-F at Trivandrum (8.5°N, 77°E, dip 0.5°N) has been investigated on a seasonal basis in sunspot maximum and minimum years in terms of the growth rate of irregularities by the generalized collisional Rayleigh-Taylor (GRT) instability mechanism which includes the gravitational and cross-field instability terms.
B. V. Krishna Murthy, K. S. V. Subbarao
openaire +4 more sources
Letter to the Editor: Post-midnight onset of spread-F at Kodaikanal during the June solstice of solar minimum [PDF]
Annales Geophysicae, 1999 At dip equatorial stations in the Indian zone, spread-F conditions are known to develop preferentially around midnight during the June solstice (northern summer) months of low solar activity, in association with a distinct increase in F layer height ...
J. H. Sastri
doaj +1 more source
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 +1 more source
Geophysical Research Letters, 1976 A numerical simulation of the non‐linear evolution of the collisional Rayleigh‐Taylor instability using a set of equations appropriate for the equatorial F region ionosphere has been performed. Our results show that the irregularities produced by the instability grow on the bottomside of the F region peak, as predicted by linear theory, and then the ...
Anthony J. Scannapieco +1 more
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