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Studies of sporadic E (E s ) associated with the main ionospheric trough
Author(s) -
Rodger A. S.,
Morrell C.,
Dudeney J. R.
Publication year - 1983
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs018i006p00937
Subject(s) - ionosonde , trough (economics) , ionosphere , geology , midnight , geophysics , f region , bay , ionogram , sporadic e propagation , physics , plasma , astronomy , oceanography , electron density , quantum mechanics , economics , macroeconomics
The occurrence of sporadic E (E S ) under the main F region trough has been established using ionograms from a vertical incidence ionosonde at Halley Bay, Antarctica (76°S, 27°W; L = 4.2), a site well suited for such studies as the trough can be seen under a wide range of magnetic conditions and local times. Analysis shows that E S is very frequently observed under both the equatorward and poleward edges of the trough, as well as poleward of it. Before magnetic midnight, E S layers with semi‐thickness similar to those of the normal E layer are most common. This is in marked contrast to the layers seen after magnetic midnight which usually show the characteristics of thin E S layers. Additional information on the morphology and dynamics of E S layers associated with the main trough has been provided by detailed study of individual events using data from the British Antarctic Survey's advanced ionospheric sounder recently deployed at Halley Bay. A possible explanation of the observed change in the E S layer characteristics at about magnetic midnight is related to differences in the type and spectra of the precipitating particles. The effects of transport processes in the E region are also considered as a possible cause. It is shown that the redistribution of ionization by the convection electric field may be important.