PhD position in biogeochemistry/ isotope geochemistry including radiocarbon

The Institute of Geology and Mineralogy at the University of Cologne, Germany, invites applications for a 3-year PhD project in carbon dynamics in arctic permafrost. The position will be based in the Organic Geochemistry & Radiocarbon group, which is part of the interdisciplinary cosmogenic nuclide-dating center CologneAMS.


Global warming is most pronounced in the Arctic, which will have significant effects on the large carbon stocks stored in permafrost soils and sediments the circumpolar region. As a consequence of permafrost thaw, this large carbon pool is exposed to degradation processes resulting in the release of greenhouse gases to the atmosphere. Fluxes and sources of CO2 and CH4 from thawing permafrost depend strongly on the composition and degradability of the organic material as well as various environmental factors. The PhD project aims at determining sources of CO2 and CH4 released from thawing permafrost using carbon isotopic analyses both in the field as well as in laboratory experiments. The project involves technical developments/improvements of analytical devices to measure 14C contents of CO2 and CH4. In addition, organic geochemical methods will be used to determine organic sources and stage of degradation as well as microbial consortia.

Your Tasks

  • Planning and conducting field measurements and sampling of CO2 and CH4 for isotopic analyses
  • Analyzing organic matter composition and microbial communities using organic-geochemical techniques
  • Developing new and improving existing sampling devices (e.g. molecular sieve cartridges and vacuum systems) for 14C analysis of CO2 and CH4
  • Contributing to AMS 14C analysis in collaboration with the nuclear physics group
  • Organizing fieldwork including logistics
  • Data analysis and publishing of results in peer-reviewed journals

Your Profile

  • M.Sc. in geosciences, environmental sciences, chemistry or related subjects
  • Pronounced interest and excellent background in biogeochemical cycles
  • Practical experience in isotope geochemical and/or organic geochemical methods
  • Willing to participate in several 2-6 week long field campaigns to the Arctic (Siberia, Svalbard)
  • Ability to work self-organized as well as in a team
  • Strong interest in technical and analytical work (including method development)
  • Good knowledge of spoken and written English


The position is limited to 3 years and will start in April/May 2020. The salary will be according to German Public Service Sector salary group TV-L 13, 65%. For further information please contact Prof. Dr. Janet Rethemeyer. As Ph.D. student you will be member of the graduate school of geosciences or another graduate school. The University of Cologne is committed to equal opportunities and diversity.

Application: Please send your application as a single pdf document (including motivation, CV, certificates, names of 1-2 referees) by email to Prof. Dr. Janet Rethemeyer until 20. Feb. 2020.

posted: 14 January 2020     Please mention EARTHWORKS when responding to this advertisement.