I am a geodesist who uses numerical forward models in conjunction with in-situ and satellite observations to explore the dynamics of the ocean, the atmosphere, and the solid Earth. More specifically, I study rapid mass changes in the Earth system, sea level and tidal phenomena, both in their own right and in terms of their impact on Earth's gravity field or other global geodetic parameters, such as polar motion. Numerical modeling work on supercomputers is an important component of my research.