Trends in the Mesosphere and Lower Thermosphere
Thomas Ulich and Esa Turunen
Sodankylä Geophysical Observatory, Tähteläntie 112, Sodankylä, Finland
In the recent years, studies of atmospheric long-term behaviour has become rather trendy. Following a study hinting on a possible connection between solar activity and climate parameters, authors have studied their long-term data sets for signals of external or anthropogenic forcing of the atmosphere. Here we will review trends found in the mesosphere and the lower thermosphere. We will address a few open questions connected to these trends.