PhD Candidate (m/f/d) | Hybrid Modelling for Ecosystem-Atmosphere Carbon & Water Fluxes

Background and position description

The Max Planck Institute for Biogeochemistry (MPI-BGC) in Jena is dedicated to interdisciplinary fundamental research in the field of Earth system sciences with a focus on climate and ecosystems. The internationally renowned institute, which currently employs around 250 people, celebrated its 25th anniversary in 2022. Jena is known for its high-tech industry, internationally renowned research institutions and a modern university, but it also has a beautiful natural setting in the green Saale valley with steep limestone slopes. The city of Jena has an active student scene and a diverse cultural life. Within the framework of the GENAI-X project, the Model-Data Integration group within the Department of Biogeochemical Integration at the Max Planck Institute for Biogeochemistry is looking for a PhD Candidate (m/f/d) Hybrid Modelling for Ecosystem-Atmosphere Carbon & Water Fluxes (m/f/d) in full time; fixed-term, 3-year position.

Originating in the ELLIS Unit Jena, the research project »AI Generalizability in Non-stationary Environmental Regimes: The Case of Hydro-climatic Extremes (GENAI-X)«, funded by the Carl-Zeiss-Stiftung, addresses a fundamental AI challenge: achieving robust model generalizability in non-stationary environmental systems. Focusing on hydro-climatic extremes and their impacts, a multidisciplinary team from Friedrich Schiller University Jena, the Max Planck Institute for Biogeochemistry, the Jena University Hospital, and the Senckenberg Institute for Plant Form and Function jointly develops AI models that function reliably under constantly changing conditions. Within the framework of the GENAI-X project, we are seeking a highly motivated PhD candidate (m/f/d) to contribute to the ecosystem dynamics subproject, which develops hybrid and data-driven approaches with a strong focus on improving the representation and generalization of ML models for the dynamics of Ecosystem-Atmosphere Carbon and Water Fluxes.

Your tasks

• Build hybrid models, process-based and deep learning models, to capture ecosystem flux dynamics across space and time
• Develop generalizable models robust to climate variability, extremes, and concept shift
• Explore equation discovery and dependency-testing ideas to obtain deterministic, interpretable representations of plant carbon allocation and plant water status
• Integrate multiple Earth observation data, from eddy covariance, sap-flux, to high-resolution Earth observation satellite datasets for model training and evaluation
• Publish and present results in an interdisciplinary research network

Your profile

• Master’s degree (or equivalent) in a quantitative discipline, Earth system/environmental sciences or engineering, physics, mathematics/statistics, computer/data science, geoinformatics, geoecology or related fields
• Programming skills (Julia, Python, MATLAB) and ability to work with time series and/or geospatial data
• Motivation to work at the interface of ML and environmental process understanding; curiosity for interpretable and robust modeling; ability to work both independently and in a team
• Excellent oral and written communication skills in English

Our offer

• A scientifically stimulating PhD project, relevant for climate-change research, in a curious and diverse research team
• Strong computational and scientific infrastructure, and collaboration across disciplines within the project, the department and extramural partners
• A broad selection of learning opportunities Earth system sciences and soft skills
• A welcoming environment: we strongly encourage applications from women, underrepresented groups, and candidates with disabilities. We value diversity in backgrounds, perspectives, and experiences

This PhD position offers a unique opportunity in the field of data-driven Earth system modelling in close collaboration with domain and machine learning experts. The position is expected to start in June 2026 and will be embedded in collaborations across the ELLIS Unit Jena.

Part-time work is generally possible. The position will be evaluated and graded following the collective agreement according to TVöD Bund. The Max Planck Society (MPS) strives for gender equality and diversity. The MPS aims to increase the proportion of women in areas where they are underrepresented. Women are therefore explicitly encouraged to apply. We welcome applications from all fields. The Max Planck Society has set itself the goal of employing more severely disabled people. Applications from severely disabled persons are expressly encouraged.

Your application

For further inquiries, please contact Nuno Carvalhais ( ). Are you interested? Please send us your application with cover letter, curriculum vitae as well as names and contact information of two references summarised in a PDF file (max. 10 MB) by April 09, 2026 , quoting the reference number 02/2026 by e-mail to or to the Max Planck Institute for Biogeochemistry.

Max-Planck-Institut für Biogeochemie
Personalbüro: Kennwort “Doktorand”
Hans-Knöll-Straße 10
07745 Jena
Germany

We ask that you do not use application folders, but only submit copies, as your documents will be destroyed in accordance with data protection regulations after the application process has been completed. We look forward to receiving your application!