Type-1 echoes from the mid-latitude E-Region ionosphere
Item
Title (Dublin Core)
Type-1 echoes from the mid-latitude E-Region ionosphere
Description (Dublin Core)
This paper presents more data on the properties of type-1 irregularities in the nighttime mid-latitude <i>E-</i>region ionosphere. The measurements were made with a 50-MHz Doppler radar system operating in Crete, Greece. The type-1 echoes last from several seconds to a few minutes and are characterized by narrow Doppler spectra with peaks corresponding to wave phase velocities of 250–350 m/s. The average velocity of 285 m/s is about 20% lower than nominal <i>E</i>-region ion-acoustic speeds, probably because of the presence of heavy metallic ions in the sporadic-<i>E</i>-layers that appear to be associated with the mid-latitude plasma instabilities. Sometimes the type-1 echoes are combined with a broad spectrum of type-2 echoes; at other times they dominate the spectrum or may appear in the absence of any type-2 spectral component. We believe these echoes are due to the modified two-stream plasma instability driven by a polarization electric field that must be larger than 10 mV/m. This field is similar in nature to the equatorial electrojet polarization field and can arise when patchy nighttime sporadic-<i>E</i>-layers have the right geometry.
Creator (Dublin Core)
Haldoupis, C.
Farley, D. T.
Schlegel, K.
Date (Dublin Core)
2018-09-27
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.1007/s00585-997-0908-2
https://angeo.copernicus.org/articles/15/908/1997/
Source (Dublin Core)
eISSN: 1432-0576
Language (Dublin Core)
eng
