Curious to understand how the atmosphere above your head kneads the Earth's crust beneath your feed?

PhD position at BFO and GPI within the RING research group

Background

Earth's crust undergoes deformation caused by the forces of air-pressure acting on the Earth's surface. Due to the unrest of the atmosphere, this is continuously ongoing and occasionally shows strong transient disturbances of seismic recordings. The effect is clearly identified in seismometer recordings and currently limits the signal-to-noise ratio for observations of toroidal normal modes of the Earth. The signal-to-noise ration of measurements of rotation is impacted vene more severely. For this reason we have a strong desire to understand the underlying mechanisms in a quantitative and deterministic way, which shall allow us to mitigate the disturbances in normal mode data in the long run.

With research projects at BFO we have demonstrated that the atmosphere induces background signals in long-period seismic recordings. For vertical component data this is due to Newtonian attraction by the atmosphere and mitigation procedures using a correction based on atmospheric pressure recordings are successful (Lepage et al. 2023, GJI, DOI: 10.1093/gji/ggad052). For horizontal component data we have demonstrated simple coupling mechanisms between surface air pressure as well as pressure gradients and recorded tilt (rotation, see Zürn et al. 2022, GJI, DOI: 10.1093/gji/ggab336). However, we still lack observations of lateral pressure variations. Data in the required frequency range and the necessary spatial resolution have not been recorded before. The data set, which we just started to collect, will be unique in that sense and will open windows to new research also in atmospheric dynamics.

The PhD project

As the successful candidate you will contribute to the deployment and operation of a large-N array of autonomous barometers in the vicinity of Black Forest Observatory (BFO), which was started in 2026. From the such obtained data parametric descriptions of time-varying lateral gradients of air-pressure shall be derived. This should lead to the development of models of how atmospheric pressure loading on the Earths surface couples into deformation of the Earths crust. 

A particular appeal of the project is that you will be involved in the entire process of a scientific investigation — from designing and carrying out the relevant measurements, through the analysis of the collected data and the creation of models to describe the interactions, all the way to the application of these models. You will be breaking new ground right from the start by collecting air pressure data using a large array of barometers. To date, the dynamics of the atmosphere on these temporal and spatial scales have remained largely unexplored. The measurement results are also of great interest to atmospheric physicists, and you will have the opportunity to exchange ideas across disciplinary boundaries, even beyond the scope of this research consortium (we have established contacts with a research group at the KNMI in the Netherlands for this purpose). The deformations of the Earth’s crust caused by the atmosphere are particularly disruptive to measurements of geometric rotation. The latter is the focus of research projects within the RING consortium. The other project groups, for example, are urgently seeking an answer to the question of whether the background noise observed in the large ring lasers (G-Ring in Wettzell, ROMY in Fürstenfeldbruck) is of an instrumental nature (i.e., generated by the ring laser itself) or already reflects actual motion caused by the ongoing deformation of the Earth’s crust. You will make a significant contribution to answering this question.

The highly sensitive, autonomous barometer modules we use were developed at BFO by Rudolf Widmer-Schnidrig (doi: 10.5445/IR/1000191379). You’ll benefit from the fact that approximately 70 barometers are already installed and produce data, so you’ll be able to work with measurement data from day one. Since you’re pursuing a Ph.D., you should start writing publications as early as possible. However, we still have ideas for further improvements to the barometer modules that we’d like to implement with a partner company. Contributing to this effort might be right up your alley.

You will also familiarize yourself with new subject areas. With a degree in physics or geophysics, you have the necessary background for this. You will become familiar with the concepts and technical tools (measuring instruments, computer programs, data formats) of seismology. Together, we will deepen our understanding of the physics of the atmosphere. Our contacts with the IMK-TRO at KIT and the KNMI in the Netherlands will be helpful in this regard. To understand the elastic response of the Earth’s crust to the atmosphere, you will study continuum mechanics. Depending on the initial findings from the analysis of air pressure data, the project also offers the potential to model the deformation of the Earth’s crust using numerical methods (finite elements). The university environment at KIT offers opportunities to try out and improve your skills in teaching students. Through your participation in courses, you will impart knowledge and skills in geophysics that you will have acquired yourself beforehand (if applicable, in the course for which you lead a tutorial group).

Within the RING consortium, you will be part of an international group of approximately 10 early-career researchers (see the job descriptions on the RING website). You will be in frequent contact with the others and will also organize and conduct workshops and training sessions. The first workshop takes place in Tutzing from October 25 to October 28, 2026. At the Geophysical Institute (GPI) at KIT, you will also be part of an international research group. Our working language is English. The courses in our international master’s program are taught in English.

For the measurements, you will be out in the field installing barometers and collecting data. We have funding for a student assistant who can support you. Your trips from Karlsruhe will also take you regularly to the BFO, where you’ll have the opportunity to exchange ideas with the researchers on site. Our research group at the GPI meets weekly to discuss current issues and share research findings. You will develop and pursue your own ideas and make suggestions for the next steps. Enthusiasm for the research question and the scientific methods used to investigate it is certainly helpful, if not essential.

Requirements

  • You hold a Master’s degree in geophysics, physics or a related discipline.
  • You are eager to conduct independent research and have demonstrated your excellent skills in analyzing problems and developing solutions.
  • Proficiency in computer based data analysis (specifically time series analysis) and programming (preferably Python) are expected.
  • You are comfortable with carrying out field work and handling delicate measuring equipment.
  • A driver’s license is required.
  • Experience in the fields of seismology, atmospheric dynamics, and/or elasticity theory are a definite plus.
  • You are open minded and active and you have a good command of the English language.
  • Knowledge of the German language can be an advantage.

Links and references

Contact 

If you are interested get in touch with Thomas Forbriger.