The Satellite Data Analysis Working Group focuses on investigating the interactions between the atmosphere and ionosphere across different altitudes and scales – particularly in the transition region from 100 to 300 kilometers altitude where Earth’s atmosphere meets space.
We evaluate observational data from satellites in low and very low Earth orbits (LEO and VLEO) and combine them with ground-based measurements and simulation results. One of our main goals is to investigate large-scale variations in the mesosphere and lower thermosphere (MLT) and their influence on the ionosphere-thermosphere (IT) system. We also analyze how small- to regional-scale disturbances arise in the MLT and how they are related to the variability of the ionosphere. In addition to employing and developing empirical models of the IT system, the working group is involved in scientific consortia of current and planned LEO and VLEO satellite missions.
The thermosphere and ionosphere are affected by energy from the sun and the magnetosphere, as well as by atmospheric waves that originate in the lower atmosphere, such as planetary waves, tides, or gravity waves. These waves can reach the lower thermosphere and ionosphere where they can set up electromagnetic fields, change the ionospheric current flow, and modify the plasma distribution. Some of these atmospheric waves even reach the upper thermosphere, where they can significantly influence the IT characteristics. To investigate these coupling processes, we evaluate atmospheric reanalysis data as well as regional ground-based and global satellite-based measurements using modern analysis methods.
Satellite observations show that regional ionospheric disturbances—such as equatorial post-sunset plasma irregularities—may be associated with atmospheric waves originating in the lower atmosphere. To better understand and potentially predict the irregularities, we investigate their formation by combining satellite-based measurements with ground-based measurements. Using long-term observations of LEO missions, such as Swarm and CHAMP, we also develop statistical models of their occurrence rate.
The SAT working group collaborates with national and international partners to develop new mission concepts for very low Earth orbits (VLEO, 100–300 km). These missions are intended to provide continuous in situ observations of this largely unexplored transition region between Earth atmosphere and space. Numerical simulations help to optimize mission profiles and orbits in order to maximize scientific benefit. Together with the Optical and Rocket Sounding Department at IAP, we are developing instrument concepts that will enable high-resolution measurements of neutral and electron density in the lower thermosphere, which has been little explored to date.