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Anomalous ion layers in the high‐latitude winter E region
Author(s) -
Kirkwood S.
Publication year - 1991
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/91gl01225
Subject(s) - zenith , atmospheric sciences , altitude (triangle) , solar zenith angle , daytime , ionization , radiation , precipitation , latitude , environmental science , ionosphere , astrophysics , physics , ion , meteorology , astronomy , optics , quantum mechanics , geometry , mathematics
The characteristics of an anomalous ionisation layer appearing during winter daytime at 69.6°N, 19.2°E are described. The layer is located at about 100 km altitude, is about 15 km thick and appears not to result from energetic particle precipitation. It has been observed on 80% of winter days when measurements have been made and was usually present for several hours on each of those days, whenever the solar zenith angle was less than 93°. The layer cannot be explained by ionisation of the major atmospheric constituents by solar EUV or X‐ray radiation. Possible explanations in terms of the minor constituents NO and metallic atoms are considered but much larger number densities of those constituents would be required than have been observed.