Long-term Evolution of F2-Layer Peak Height
at Various Locations: a Comparison
Thomas Ulich and Esa Turunen
Geophysical Observatory, FIN-99600 Sodankylä, Finland
Increased concentrations of greenhouse gases in the air cause a cooling of
the strato-, meso-, and thermosphere (Roble and Dickinson, 1989); the
atmosphere is expected to shrink. Rishbeth (1990) predicted a lowering of
the peak height of the ionospheric F2-layer which was confirmed for
mid-latitudes by Bremer (1992). In the present study we compare long-term
data from Sodankylä, Finland, (high latitude, 67.4N, 26.7E) with
Bremer's results and other ionosonde records. The evolution of the F2 peak
height varies considerably among the stations studied in this work; cooling
of the upper atmosphere is not observed at all locations.
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