Ph.D. positions in ocean ecological/biogeochemical modeling

100%, Zurich, fixed-term

We are searching for two highly motivated and curious Ph.D. students to join the Environmental Physics Group at ETH Zurich, a vibrant interdisciplinary team of researchers studying the ocean, its physics, biogeochemistry, and ecology and their interactions with climate. A key motivation driving our work is to better understand and quantify how climate change will impact the ocean, its biogeochemistry, and its ecology, and how these changes may feed back on climate.

These two positions are offered in the framework of the recently funded Horizon-Europe BioGeoSea project.

BioGeoSea brings together more than 15 partner institutions across Europe, with the goal to improve our understanding of key biogeochemical essential ocean observables (EOVs) and their spatiotemporal dynamics and observability. A crucial expected outcome of the project is the better knowledge how to observe a set of biogeochemical EOVs that were identified to be critical indicators for the assessment and monitoring of oceanhealth. A second objective of the project is to improve the representation of the ecological/biogeochemical processes that control these EOVs in ocean biogeochemistry and climate models, thereby facilitating the interpretation of past and present trends and variability in these variables. The two Ph.D. positions will contribute to both objectives.

Job description

Ph.D. position 1:

The first of the two doctoral students will work primarily on the marine nitrogen cycle and how it is affected by extreme conditions. The focus will be on the production, consumption and outgassing of nitrous oxide (N2O), a very potent greenhouse gas. But we will be looking also at several other processes governing the marine nitrogen cycle, including N2-fixation, denitrification, and anammox, and how they respond to extremes associated with heat (marine heatwaves), low oxygen and/or high acidity. The work, involving models and observations, will start in the oxygen deficient waters of the eastern tropical Pacific, where a large portion of the marine N2O is emitted into the atmosphere, but we plan to extend this also to other regions of the world.

Ph.D. position 2:

The second doctoral student will work on the improvement of zooplankton processes in our models, focusing on their role in structuring the phytoplankton community and in governing the efficiency of the biological carbon pump. The student will further study food-web interactions and transfer of matter across trophic levels. An essential component will be the assessment of the model results with observations, as well the use of the models to design improved observational strategies. The work will focus on the Southern Ocean, but with an eye toward the application of this improved model across the global ocean.

Both doctoral students will work with configurations of the ETHZ version of the Regional Oceanic Modeling System (ROMS) that we have developed over the last decade.

Profile

As the ideal Ph.D. student, you have a master’s degree in atmospheric, oceanic and/or climate sciences (PhD 1, PhD2) and/or marine ecology or biology (PhD 2), physics, computational sciences or a closely related discipline with a strong interest in numerical and quantitative science. Fluency in English and good communication skills is a must, as is experience with a higher programming language (e.g., Fortran, C, Matlab, Python). You like to work as part of a team, and love to further your understanding of how the Earth works. You will work in the Environmental Physics group of Prof. Nicolas Gruber, and will be co-supervised by Dr. Meike Vogt.

Workplace

We offer

Training opportunities with leading experts in modelling, biogeochemical cycles, and ocean processes.
Support programmes and networking opportunities such as assisting at international conferences.
An interdisciplinary research group with different interests on processes occurring in the ocean.
A supportive working environment that values the well-being of the whole group.
Flexible working hours and possibility of working from home, promoting a healthy work-life balance.

Working, teaching and research at ETH Zurich

We value diversity

In line with our values, ETH Zurich encourages an inclusive culture. We promote equality of opportunity, value diversity and nurture a working and learning environment in which the rights and dignity of all our staff and students are respected. Visit our Equal Opportunities and Diversity website to find out how we ensure a fair and open environment that allows everyone to grow and flourish.

Curious? So are we.

We look forward to receiving your online application until August 15, 2025 including:

a CV
a statement of research interest
the names of two academic referees

The position stays open until filled. The positions are funded for a total of three years, with the opportunity to extend the contract beyond the lifetime of the project.

For further information about the position please contact Prof. Nicolas Gruber at nicolas.gruber[at]env.ethz.ch or visit our website.

About ETH Zürich

ETH Zurich is one of the world’s leading universities specialising in science and technology. We are renowned for our excellent education, cutting-edge fundamental research and direct transfer of new knowledge into society. Over 30,000 people from more than 120 countries find our university to be a place that promotes independent thinking and an environment that inspires excellence. Located in the heart of Europe, yet forging connections all over the world, we work together to develop solutions for the global challenges of today and tomorrow.