Abstract The absorption anomaly of Lyman-alpha radiation in satellite occultation experiments is known as the fact that extinction above 100 km is much stronger than absorption by atmospheric O2 alone would explain. Additional absorption by NO or H2O has been suggested but none has been clearly identified so far. The additional absorption occurs predominantly in middle and high latitudes of the winter hemisphere, but has also been found in equatorial latitudes. Recent measurements of NO would explain the Lyman-alpha absorption anomaly. The high densities of the additional Lyman-alpha absorber at lower latitudes could be explained by transport processes through global circulation systems of the higher thermosphere. Structural variations of the neutral gas derived from occultation measurements seem to indicate that thermospheric low pressure systems in mid latitudes modulate the transport of tracer constituents and heat energy from higher latitudes to the equator.
The Lyman-alpha absorption anomaly in satellite occulation measurements as a tracer for some thermospheric composition variations
Advances in Space Research ; 3 , 1 ; 103-106
1983-01-01
4 pages
Article (Journal)
Electronic Resource
English
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