Results 191 to 200 of about 92,748 (240)

Equatorial spread-F at Ibadan, Nigeria

Journal of Atmospheric and Terrestrial Physics, 1961
Abstract The characteristics of equatorial spread-F at Ibadan (magnetic latitude 3°S) are investigated including nocturnal, seasonal, solar-cycle and magnetic disturbance variations; and all of these are found to show marked correlations with corresponding changes in the height of the layer. For example spreading begins shortly after the evening rise
Lyon, AJ, Skinner, NJ, Wright, RW
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Role of equatorial ionization anomaly in the initiation of equatorial spread F

Journal of Geophysical Research: Space Physics, 1988
A comparative study is made of the changes in the latitudinal structure of the F region electron density at fixed altitudes in the Indian equatorial region on days with and without postsunset onset of equatorial spread F, using (N‐h) profile data of Ahmedabad (dip latitude 18.6°N), Waltair (dip latitude 10.6°N), and Kodaikanal (dip latitude 1.5°N).
R. Raghavarao, M. Nageswararao, J. Hanumath Sastri, G. D. Vyas, M. Sriramarao   +4 more
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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
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Equatorial spread-F (ESF) and vertical winds

Journal of Atmospheric and Solar-Terrestrial Physics, 1999
Abstract The Equatorial Spread-F (ESF) phenomenon is recorded in ionograms as a hierarchy of plasma instabilities in the F-layer of the equatorial ionosphere. The ESF is characterized by irregularities in the plasma (electron and ion) density and electric field distributions perpendicular to the Earth’s magnetic field.
R. Raghavarao, R. Suhasini, H.G. Mayr, W.R. Hoegy, L.E. Wharton   +4 more
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On the cause of equatorial spreadF

Journal of Geophysical Research, 1973
It is suggested that convective electric fields in the equatorial ionosphere are generated by neutral winds (zonal or meridional) which act on regions having structure in their field aligned Pedersen conductivity integrals. The conductivity structure is presumably caused by long-lived metallic ions concentrated irregularly below the F layer at ...
W. B. Hanson, J. P. McClure, D. L. Sterling   +2 more
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On the nature of equatorial spreadF

Journal of Geophysical Research, 1961
Ionospheric propagation via scattering from the F region was sought at 50 Mc/s over a transequatorial path (with midpoint near Huancayo, Peru) employing a 2580-km transmitter-receiver separation. Propagation via F scatter was present over this path about 10 per cent of the time, though only at night.
Robert Cohen, Kenneth L. Bowles
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Radio wave heating and equatorial spread-F

Journal of Atmospheric and Terrestrial Physics, 1987
Abstract High frequency radio waves passing through the F -region of the ionosphere can modify the spectrum of spread- F irregularities via a four wave parametric interaction. Non-linear coupling arises through the thermal gradient force. The growth rate is a sensitive function of the angle θ between the wave vectors of the incident wave and the ...
V.N. Laxmi, V.K. Tripathi
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Equatorial spread-F campaign over SHAR

Journal of Atmospheric and Solar-Terrestrial Physics, 1997
Abstract A RH-560 rocket instrumented with a Langmuir Probe and two pairs of double probes was launched from SHAR (dip 14 ° N) at 2130 hr LT (1ST) on 4 October 1988 during spread-F conditions. As a part of this campaign VHF scintillations at 136.1 MHz were also recorded, using the beacon onboard the geostationary satellite ETS-II (130 ° E).
H. Chandra, G.D. Vyas, H.S.S. Sinha, S. Prakash, R.N. Misra   +4 more
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Control of equatorial spread-F by the F-layer height

Journal of Atmospheric and Terrestrial Physics, 1966
Abstract The dependence of equatorial spread-F occurrence on the height of the layer is examined in detail in the case of two equatorial stations viz. Kodaikanal and Huancayo, lying close to the magnetic equator. The percentage of occurrence associated with different heights is found to vary with time, season and longitude.
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Equatorial Spread-F and Tropospheric Tropical Disturbances

Journal of the Atmospheric Sciences, 1966
Equatorial spread-F and tropical disturbances, supplying data on typhoon, geomagnetic activity and atmospheric pressure ...
Kaichi Maeda, Victor L. Badillo
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