Mesospherictube trends at mid-latitudes derived from LF radio propagation experiments Original Research Article

From radio wave observations in the LF range (phase height and absorption measurements) at mid-latitudes longterm trends have been derived for the meso- and lower thermosphere. In the regression analyses used the solar and geomagnetically introduced parts have also to be considered. From these trends information about mesospheric temperature trends have been estimated with a pronounced cooling of the mesosphere during the last decades (up to about −0.45 K/year in summer and up to about −0.35 K/year in winter). The derived temperature trends are in reasonable agreement with other experimental results. Model results taken into account the well-known trends in CO2 and ozone show also a mesospheric cooling, their trends are however smaller than the experimental results.