Results 181 to 190 of about 92,748 (240)

The belt of equatorial spread-F

Journal of Atmospheric and Terrestrial Physics, 1960
Abstract The morphology of the belt of equatorial spread-F at sunspot maximum is investigated, using I.G.Y. data, for magnetically quiet and magnetically disturbed conditions respectively. The belt is found to extend from about 30°S to 30°N in magnetic latitude and to have a region of very high incidence, exceeding 90 per cent for the early part of ...
Lyon, AJ, Skinner, NJ, Wright, RWH
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Duration of equatorial spread F

Nature, 1975
IT is well established1–3 that the spread-F phenomenon, which is observed as diffuse echoes on the ionograms is a common feature during night time between the dip latitudes 20°N and 20°S. Based on the study of ionograms and published monthly f0F2 bulletins, morphological features of spread F have been reported for several equatorial stations1,4–10 ...
V. V. SOMAYAJULU, K. SEN GUPTA, B. V. KRISHNA MURTHY   +2 more
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A study of equatorial spread-F

Journal of Atmospheric and Terrestrial Physics, 1963
Data from seven stations ranging in magnetic dip from 0° to 44°N have been analysed to study night time and seasonal variations of spread-F through nearly half a solar cycle. It is observed that the inhibition of spread-F due to geomagnetic activity is maximum in the equinoxes.
S. Rangaswamy, K.B. Kapasi
openaire   +1 more source

Modeling the Impact of Metallic Ion Layers on Equatorial Spread F With SAMI3/ESF

Geophysical Research Letters, 2020
The impact of E region metal ion layers on the development of equatorial plasma bubbles is investigated using the SAMI3/ESF model. We find that metal ion layers reduce the growth rate of the generalized Rayleigh‐Taylor instability (GRTI) and act to ...
J. Huba, J. Krall, D. Drob
semanticscholar   +1 more source

Artificial control of equatorial spread-F

Journal of Atmospheric and Terrestrial Physics, 1978
Abstract We have studied the influence of a large amplitude electric field oscillating near the upper hybrid frequency on the dispersion characteristics of low frequency Rayleigh-Taylor modes and collisional drift modes. Since these modes have been proposed as principal constituents of spread- F , we investigate the conditions for the parametric ...
S Bujarbarua, A Sen
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A Statistical Study on The Local Time Dependence of Equatorial Spread F (ESF) Irregularities and Their Relation to Low‐Latitude Es Layers Under Geomagnetic Storms

Journal of Geophysical Research - Space Physics, 2020
In this paper, we present a study on the local time dependence of equatorial spread F (ESF) irregularities and their relation to low‐latitude Es layers in response to geomagnetic storms using simultaneous observations of two ionosondes one located at ...
Ram Singh, S. Sripathi
semanticscholar   +1 more source

On the Genesis of Postmidnight Equatorial Spread F: Results for the American/Peruvian Sector

Geophysical Research Letters, 2018
Previous studies of the Earth's low‐latitude ionosphere using in situ measurements made by sensors on the Communication/Navigation Outage Forecasting System (C/NOFS) satellite showed an unexpected predominance of equatorial spread F (ESF) events in the ...
Weijia Zhan, F. Rodrigues, M. Milla
semanticscholar   +1 more source

Equatorial Spread-F and Magnetic Activity

Nature, 1958
IT is well known that the ionospheric spread-F condition is extremely common at night in equatorial regions. At Ibadan, Nigeria (latitude 7½°N.), this has been especially so during the past 2½ years of high sunspot activity. It is believed that the same irregularities which produce the wide spread of scattered echoes from the F-region are also ...
A. J. LYON, N. J. SKINNER, R. W. WRIGHT
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Geomorphology of spread F and characteristics of equatorial spread F

Journal of Geophysical Research, 1959
Between magnetic latitudes 20°N and 20°S there is a well defined region where spread F is a normal occurrence on magnetically quiet days. Equatorial spread F is a night-time phenomenon that begins between 1900 and 2200 by a characteristic doubling of the layer and an increase in virtual height, indicating a vertical velocity.
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Equatorial spread-F and solar activity

Journal of Atmospheric and Terrestrial Physics, 1964
Abstract The effect of solar activity on equatorial spread- F has been studied using the published tables of f 0 F 2 from six Afro-Asian stations. The strong negative correlation between equatorial spread- F and magnetic activity observed during sunspot maximum is no longer significant during low sunspot years.
S. Rangaswamy, K.B. Kapasi
openaire   +1 more source