Evidence of the impacts of climate change on the middle and upper atmosphere is increasing, making clear the critical need for observational data to monitor and understand trends. A contraction of the stratosphere and a decrease of density in the upper atmosphere have been quantified, but we still face significant limitations on the data available to assess it. Past efforts to study trends have focused mainly on the atmospheric levels separately (mesosphere, thermosphere, ionosphere), where cooling and contraction have also been observed.
Monitoring these trends and their impacts on satellites and space debris needs a continued effort that provides better data and improved insight into the consequences that increased CO2 has on the middle and upper atmosphere. However, we lack satellite missions capable of doing it. Also, disentangling the role of other factors in those changes, such as the solar cycle, is essential.
This session concerns changes in the structure of the atmosphere through all their dimensions, heating and cooling, changes in atmospheric circulation, and their impacts, for example, on the drag of space objects. We especially welcome presentations about existing data and measurements to monitor middle and upper atmosphere trends, evaluating monitoring gaps, and studies on documenting, modelling or projecting changes and their driving.