This joint session invites papers that are related to coupling processes in the middle atmosphere and lower thermosphere. The mesosphere/lower thermosphere (MLT) is influenced by the Sun in a much more complex and significant way than hitherto anticipated. We therefore in particular encourage contributions related to the Climate and Weather of the Sun-Earth System (CAWSES) program initiated by SCOSTEP. One corner stone of CAWSES are coupling processes in the middle atmosphere such as tides, planetary waves, gravity waves; chemistry; neutral-ion coupling; and the interaction of the various processes involved.

Contributions using ground- and space-based measurements, theory and modeling results are encouraged that focus on aspects of:
1. the influence of the Sun on Earth's atmosphere and decadal variations in the MLT.
2. coupling processes between the mesosphere and lower thermosphere and regions below and above.