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Vol. 1 (1998 year), No. 2

Vlaskov V.A., Bogolubov A.A.
Polar mesospheric summer echo observations by a partial reflection radar

An interesting phenomenon occurring in the polar summer mesosphere, named Polar Mesospheric Summer Echoes - PMSE is considered in the paper. On the example of long-term data of a partial reflection radar of the Polar Geophysical Institute (PGI-PRE-radar) in Tumanny (68.9В° N, 35.8В° E) reflections on frequency 2.7 РњHz from heights of the mesosphere in summer periods are analysed. Peculiarities of a reflected signal in PMSE periods are shown. The analysis of data has shown precise connection of PMSE with tides at considered heights, in particular, anticorrelation between probability of PMSE occurrence and meridional component of semi-diurnal tide. Comparison of the data of three radars: EISCAT VHF (224 РњHz), ALOMAR-SOUSY (53,5 РњHz) and PGI-PRE shows that in PMSE periods irregularities of electron concentration with scales from ~100m up to ~10sm are formed at the mesosphere heights. In the paper the structure of reflection fluctuations in PMSE periods is investigated and on the basis of the analysis an attempt to receive information on PMSE irregularity dynamics is made. The profiles of electron density in the ionosphere received by partial reflection radar are analysed. Estimations of possible changes of aeronomic process efficiency during the PMSE period connected with temperature are given. Preliminary conclusions of a role of atmospheric turbulence are made.

(in Russian, стр.20, fig. 12, tables. 2, ref 32, MS Word 95, MS Word 95 621 Kb)