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Title: Condor equatorial spread F-italic Campaign: Overview and results of the large-scale measurements

During the Condor campaign a number of instruments were set up in Peru to support the rocket experiments. In this series of papers we report on the results of the experiments designed to study the equatorial F-italic region. In this overview paper we summarize the main results as well as report upon the macroscopic developments of spread F-italic as evidenced by data from backscatter radars, from scintillation observations, and from digital ionosonde measurements. In this latter regard, we argue here that at least two factors other than the classical gravitational Rayleigh-Taylor plasma instability process must operate to yield the longest-scale horizontal organization of spread F-italic structures. The horizontal scale typical of plume separation distances can be explained by invoking the effect of a shear in the plasma flow, although detailed comparison with theory seems to require shear frequencies a bit higher than observations indicate. On the other hand, the largest-scale organization or modulation of the scattering layer cannot be explained by the shear theory and must be due to local time variations in the ionospheric drift or to gravity wave induced vertical motions. Using simultaneous rocket and radar data, we were also able to confirm the oft quoted hypothesis thatmore » rapid overhead height variations in the scattering region over Jicamarca are primarily spatial structures advecting overhead. The detailed rocket-radar comparison verified several other earlier results and speculations, particularly those made in the PLUMEX experiments.« less
Authors:
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Publication Date:
OSTI Identifier:
5522794
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Geophys. Res.; (United States); Journal Volume: 91:A5
Research Org:
School of Electrical Engineering, Cornell University, Ithaca, New York
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; SPREAD F; PLASMA DENSITY; ELECTRIC FIELDS; GEOMAGNETIC EQUATOR; IONOSPHERIC STORMS; RADAR; SCINTILLATION COUNTING; SHEAR; COUNTING TECHNIQUES; EARTH ATMOSPHERE; F REGION; IONOSPHERE; MEASURING INSTRUMENTS; PLANETARY IONOSPHERES; RANGE FINDERS 640201* -- Atmospheric Physics-- Auroral, Ionospheric, & Magetospheric Phenomena