In the frame of the DFG-project “PycnoTrap” on hydrodynamical drivers of carbon cycling in aquatic ecosystems we are inviting applications for a PhD position in close collaboration with a second PhD position in microbiology. The successful candidate will be part of an interdisciplinary international team with German and Siberian lakes as primary research objects. The PhD study will be focused on physical mechanisms driving the sinking and degradation of small organic particles in thermally stratified inland waters. The approaches encompass development and application of 3d particle imaging and Lagrangian modelling of particle sinking. The study will be in close collaboration with the biogeochemical and microbiological teams of the project and allowing for intense knowledge exchange between different scientific disciplines and researchers. The workplace is in Berlin-Friedrichshagen with frequent visits of the IGB at Lake Stechlin (80 km north of Berlin), where the main field site is located. Several medium-term visits to remote sites in Siberia are envisaged as part of the field work.
Inland waters such as lakes and reservoirs play a substantial role in the transport and transformation of both terrestrial and autochthonous organic carbon. The key internal pathway for aquatic carbon dynamics, i.e. sinking of particulate organic matter (POM), strongly depends on vertical density stratification of the water column, which due to atmospheric warming has increased globally during the recent past. Yet, the integral effect of water column stratification on POM transformation remains non-quantified to date. This project aims to shed light on the changing role of water column density gradients for sinking behavior of POM and hence its impact on microbial carbon cycling in inland waters.