Results 11 to 20 of about 792,165 (198)
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
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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
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Overview and summary of the Spread F Experiment (SpreadFEx) [PDF]
Annales Geophysicae, 2009 We provide here an overview of, and a summary of results arising from, an extensive experimental campaign (the Spread F Experiment, or SpreadFEx) performed from September to November 2005, with primary measurements in Brazil.
D. C. Fritts +29 more
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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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Statistical analysis of low-latitude spread F observed over Puer, China, during 2015–2016
Earth, Planets and Space, 2019 Statistical analysis of spread F (SF), recorded at Puer (PUR, 22.7° N, 101.05° E, Dip Latitude 12.9° N) during 2015–2016, was carried out to reveal its characteristics at the northern equatorial ionization anomaly.
Ting Lan +5 more
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Morphology of quantified ionospheric range spread-F over a wide range of midlatitudes in the Australian longitudinal sector [PDF]
Annales Geophysicae, 2007 Ionograms from a standard vertical-incidence ionosonde chain (nine stations), obtained over a wide range of southern latitudes (in geom.lat. range: 23°–52° S), were digitally scanned at 5-min intervals at nighttime (18:00–06:00 LT)
L. A. Hajkowicz
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Travel distance, frequency of return, and the spread of disease
Scientific Reports, 2023 Human mobility is a key driver of infectious disease spread. Recent literature has uncovered a clear pattern underlying the complexity of human mobility in cities: $$r \cdot f$$ r · f , the product of distance traveled r and frequency of return f per ...
Cate Heine +4 more
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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
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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
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Equatorial spread-F forecasting model with local factors using the long short-term memory network
Earth, Planets and Space, 2023 The predictability of the nighttime equatorial spread-F (ESF) occurrences is essential to the ionospheric disturbance warning system. In this work, we propose ESF forecasting models using two deep learning techniques: artificial neural network (ANN) and ...
Phimmasone Thammavongsy +4 more
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