Postdoc position in biology (CIFAR – Center of Excellence, Aarhus University)

Applications are invited for a two-year postdoctoral position within the Center for Ice-Free Arctic Research (CIFAR) and the Department of Biology at Aarhus University.

Rapid warming is increasing freshwater inputs to the Arctic Ocean from melting glaciers, ice sheets, and altered precipiation patterns. At the same time, sea-ice cover is declining and the duration of the open-water season is increasing. These changes are fundamentally transforming the structure and functioning of the Arctic coastal ocean. CIFAR aims to understand how the complex interplay between ice melt, terrestrial runoff, and changing ocean conditions affects Arctic coastal ecosystems and their functioning across spatial and temporal scales.

Greenland fjords are important sites of carbon cycling and can act as substantial sinks for atmospheric CO₂ during the productive summer season. Simultaneously, increasing freshwater inputs are altering the marine carbonate system and contributing to ocean acidification. Yet, our understanding of both CO₂ exchange and carbonate chemistry remains strongly biased toward the summer months, leaving major uncertainties about how these systems function across the full annual cycle.

Ongoing changes in freshwater input, stratification and sea-ice cover may alter the magnitude and seasonality of air-sea CO₂ exchange. Longer ice-free periods provide a greater window for exchange with the atmosphere, while freshwater-driven changes in carbonate chemistry and stratification can further influence the capacity of surface waters to take up CO₂. However, we know comparatively little about what happens outside of summer, making it difficult to determine annual CO₂ uptake and predict how the carbon sink may respond to continued freshening and sea ice loss.

The autumn transition is a particularly important, but poorly understood, period. As terrestrial runoff ceases and freshwater-driven stratification weakens, deeper mixing alters surface-water carbonate chemistry while waters remain exposed to the atmosphere before sea-ice formation. How important are these seasonal transitions for annual CO₂ uptake, how are they expected to change in the future, and how does their contribution compare with the strongly freshened summer period?

This postdoctoral project will address these questions by investigating seasonal carbonate system dynamics and air-sea CO₂ exchange in Greenland fjords undergoing freshening. The successful candidate will combine field observations, experiments, and existing environmental datasets to determine how freshwater inputs, mixing, biological processes, and sea-ice cover regulate carbonate chemistry and CO₂ exchange across seasons.

The postdoctoral researcher will:

• Participate in field campagins in Greenland, including collection of carbonate chemistry samples and measuring CO2 in the water column.
• Investigate seasonal changes in the marine carbonate system and controls on air-sea CO₂ exchange.
• Conduct experiments designed to disentangle the effects of freshwater input and other environmental drivers on carbonate chemistry.
• Integrate field observations, experimental results, and complementary datasets to quantify seasonal and annual CO₂ uptake in Greenland fjord systems.
• Assess how continued freshening and changing sea-ice conditions may alter the future role of Greenland fjords in the Arctic carbon cycle.

The successful candidate will have opportunity to develop independent research questions within this framework and to integrate observations and experimental approaches across the wider CIFAR research program. Ultimately, the project will help determine how the capacity for CO₂ uptake acidiciation in Greenland's rapidly changing fjords will be affected in the future.

This is a two-year postdoctoral position (37 hours/week) from 1 March 2027.

The successful candidate should have:

• A PhD in chemical oceanography, marine science, or a related discipline.
• Excellent programming skills in R and Python or similar.
• Advanced statistical and data-analysis skills.
• The ability to work independently, develop research questions, and think creatively and critically.
• Strong written and oral communication skills in English.
• An ability to work effectively in an interdisciplinary and collaborative research environment.

Experience with fieldwork in Arctic, polar, or other remote or extreme environments is highly desirable.

Experience with public dissemintaiton and outreach of research results would also be an advantage.

This position will be administered through Aarhus University. Place of employment is Center for Ice-free Arctic Research (CIFAR) at Aarhus University, Department of Biology, 1134, 220, Ole Worms Allé 1, 8000 Aarhus C, Denmark.

If you have any questions about the scientific aspects of the position, you are more than welcome to contact: professor Søren Rysgaard (rysgaard@au.dk)

All applications must be received no later than 3 November 2026.

Shortlisting is used. This means that after the deadline for applications – and with the assistance from the assessment committee chairman, and the appointment committee if necessary, – the head of department selects the candidates to be evaluated. All applicants will be notified whether or not their applications have been sent to an expert assessment committee for evaluation. The selected applicants will be informed about the composition of the committee, and each applicant is given the opportunity to comment on the part of the assessment that concerns him/her self.

Natural Sciences refers to the Ministerial Order on the Appointment of Academic Staff at Danish Universities under the Danish Ministry of Science, Technology and Innovation.

The application must be in English and include a curriculum vitae, degree certificate, a complete list of publications, a statement of future research plans and information about research activities, teaching portfolio and verified information on previous teaching experience (if any). Guidelines for applicants can be found here.

Appointment shall be in accordance with the collective labour agreement between the Danish Ministry of Taxation and the Danish Confederation of Professional Associations. Further information on qualification requirements and job content may be found in the Memorandum on Job Structure for Academic Staff at Danish Universities.

Salary and terms as agreed between the Danish Ministry of Taxation and the Confederation of Professional Unions at basic salary steps 4-8.

Aarhus University’s ambition is to be an attractive and inspiring workplace for all and to foster a culture in which each individual has opportunities to thrive, achieve and develop. We view equality and diversity as assets, and we welcome all applicants.

Research activities will be evaluated in relation to actual research time. Thus, we encourage applicants to specify periods of leave without research activities, in order to be able to subtract these periods from the span of the scientific career during the evaluation of scientific productivity.

Aarhus University offers a broad variety of services for international researchers and accompanying families, including relocation service and career counselling to expat partners. Read more here. Please find more information about entering and working in Denmark here.

Aarhus University also offers a Junior Researcher Development Programme targeted at career development for postdocs at AU. You can read more about it here.

At the Faculty of Natural Science at Aarhus University, we strive to support our scientific staff in their career development. We focus on competency development and career clarification and want to make your opportunities transparent. On our website, you can find information on all types of scientific positions, as well as the entry criteria we use when assessing candidates. You can also read more about how we can assist you in your career planning and development.

The application must be submitted via Aarhus University’s recruitment system, which can be accessed under the job advertisement on Aarhus University's website.