Long-term changes at the edge of space - Odin and a quarter of a century of shiny clouds

The Earth´s mesosphere and lower thermosphere constitute a transition region between atmosphere and space.

In order to understand the interactions governing this region, we need observables that provide direct information about relevant atmospheric processes.

Noctilucent clouds, the highest clouds on Earth, play a prominent role in this respect as they are highly sensitive to ambient atmospheric conditions. The Swedish Odin has proven to be an excellent tool for studying these clouds and the mesosphere.

After nearly a quarter of a century in orbit, Odin has provided a unique database on the clouds and related water vapour concentrations.

The postdoctoral project proposed here comprises three steps: First we will optimise retrieval tools in close collaboration with other satellite missions and machine learning applications.

Based on detailed microphysical considerations, we will then optimise the quantitative use of the clouds as tracers for mesospheric conditions.

Finally, we will utilize the entire Odin database to study the global processes that govern the mesosphere in terms of dynamical and solar forcing mechanisms.Our major science questions are:- How do noctilucent clouds vary on different time scales in the 25-year Odin dataset?- How can we utilise properties of noctilucent clouds as tracers for local atmospheric conditions?- How do solar activity and lower atmospheric dynamics control the state and the variability of the mesosphere on different time scales?