Atmospheric gravity waves in observations and models

With better models and satellite records, the interactions between tropospheric climate and the upper atmosphere are being recognised.

Climate models are extended to higher altitudes and the need for better understanding of the physical mechanisms controlling the coupling between the layers arises. Today we know that substantial momentum is transported between these layers by atmospheric Gravity Waves (GW).

Their major effects have triggered intense research lately, but the processes are poorly understood and the global picture is largely missing.

Linear wave theory tells us that the waves are filtered by the underlying wind field, but observations are needed to understand to which degree non-linear interactions are governing the process.

By bringing together two new data sets, the Swedish MATS satellite giving us global information about GW, and ESA’s Aeolus satellite observing the underlying wind, we propose to analyse the impact of the wind on the GW momentum transport.

We will compare the results both to a model that can resolve the waves, and to a climate model where the momentum transport is parameterised.

The aim is to understand to what degree the linear theory use in today’s climate models suffices to describe the momentum transport.

The first two years of the project focus on the observational data sets, while the latter two years focus on how the processes are described in models. The project consists of myself, two co-PI and extensive international collaborations.