PhD-position "Overturning the ocean''

The department of Ocean Systems (OCS) at the Royal Netherlands Institute of Sea Research (NIOZ) is looking for an enthusiastic and motivated PhD candidate to work on the exchange of lighter and denser waters between the interior Irminger Sea and the boundary current. We are looking for a highly motivated candidate with a mathematical, physical oceanography or fluid mechanics (or similar) background. You will be part of the larger Overturning in the Subpolar North Atlantic Project (OSNAP), which aims to understand mechanisms driving the Atlantic Meridional Overturning Circulation through observations.

THE INSTITUTE

NWO-NIOZ Royal Netherlands Institute for Sea Research is the Dutch national oceanographic institute and principally performs academically excellent multidisciplinary, fundamental, and frontier applied marine research addressing important scientific and societal questions pertinent to the functioning of the ocean and seas. NIOZ includes the National Marine research Facilities (NMF) department that operates a fleet of research vessels and the national pool of large seagoing equipment, and supports excellence in multidisciplinary marine research, education, and policy development.

THE DEPARTMENT

Researchers in the Department of Ocean Systems (OCS) study open-ocean processes from a variety of disciplines including physical and chemical oceanography, marine geology, paleoceanography and deep-sea ecology. We investigate the past and present ocean in order to assess its future role in the Earth system. We collect data during oceanographic research cruises and conduct experiments both at sea and in the laboratory at our home base on Texel. The department carries out work in diverse environments all around the globe, from the Antarctic to the Arctic, and from the Caribbean to the North Sea.

THE PROJECT

The Atlantic Meridional Overturning Circulation (AMOC) is a key component in our climate system. The AMOC transports relatively warm, light water northward in the upper ocean. At high latitudes, strong winter cooling transforms these light waters into denser waters. These newly formed dense waters must enter the deep boundary current, through an exchange of dense and light water, to participate in the overturning circulation. This exchange is suggested to be facilitated by small (order 10 km) ocean eddies, but the dynamics are not yet well understood and therefore poorly parameterized in climate models. It is one of the key missing processes responsible for the large uncertainties in projections of AMOC weakening under climate change. Since a weakening of the AMOC will have strong impacts on our local climate and sea level it is important to fill this knowledge gap.

Observations from the Overturning of the Subpolar North Atlantic Program (OSNAP) have shown that the Irminger Sea, east of Greenland, is a key region for the overturning. However, the observations from this moored array do not have the spatial resolution to characterize this exchange of lighter and denser water with the boundary current in detail. This project aims to understand the process of eddy driven exchange of transformed dense water and lighter boundary current water that contributes to overturning in the Irminger Sea. In this project you will 1) use high resolution glider observations to better understand the exchange between the dense convective region and the lighter boundary current, 2) use the high resolution Surface Water and Ocean Topography (SWOT) satellite data to investigate the links to eddies in the Irminger Sea, 3) with the knowledge gained from 1 and 2, analyze the import and export of lighter and denser waters in the boundary current using the moored data to understand the contribution to overturning. A better understanding of this exchange process will help to interpret AMOC variability observed in the OSNAP array and will eventually lead to more accurate projections of AMOC change in the future.

THE CANDIDATE

We are looking for a highly motivated candidate with a Masters-level degree in a natural science such as – but not limited to – physical oceanography, fluid dynamics or applied mathematics. Practical experience of ocean data analysis and scientific programming are desirable, and the willingness and aptitude to learn and develop these skills is essential. Participation in oceanographic research expedition(s) of several weeks’ duration is expected to be an important component of this project.

Candidates should be capable of independently planning and organizing their work, and should be interested in taking a leading role in directing the course of their own research within the overall framework of the project. Proficiency in spoken and written English is essential, as the candidate will present their results at international conferences, and write manuscripts to submit to peer-reviewed scientific journals.

We want to be a transparent institute with a healthy working climate and an inclusive culture, where people from diverse backgrounds and gender bring their talents and further develop these talents. We aim for inclusive decision-making processes and expect our leadership to show visible commitment, awareness of bias, and cultural intelligence.

THE CONDITIONS

• Employment of this full-time position at Royal NIOZ is by NWO-I, for a total duration of 4 years. You start with an appointment for the duration of 1 year, that, after a positive evaluation in the 9th month (Go-No go), will be extended to the full period of 4 years.

• Salary compliant with scales for PhD candidate (OIOs) CAO-WVOI (Collective Labour Agreement for Dutch Research Institutes). 

• An appointment at NIOZ as a PhD means working and learning simultaneously conform the NIOZ PhD policy.

• 338 annualized holiday hours for a full-time 40-hour work week.

• Pension scheme via ABP, 8% holiday allowance and a year-end bonus of 8.33%.

• 2nd class public transportation travel is reimbursed 100%.

• Employment benefits plan to exchange a portion of your salary for days off or vice versa or can be used to purchase a bicycle with tax benefits.

• We offer relocation expenses for employees coming from abroad and support with finding accommodation.

MORE INFORMATION

Please enclose: a CV, a one-page cover letter explaining your interest in the position, names and contact information of 2 references, and if possible a recent writing sample (such as a written report of research during your master’s degree), before the closing date. The cover letter (max one-page A4) should discuss your motivation for this PhD position including how you meet some or all of the preferred criteria.

For additional information about this vacancy, please contact the project leader Femke de Jong or the department head Gert-Jan Reichart. For additional information about the procedure, please send an e-mail to working@nioz.nl

Interviews are scheduled for end of September 2025. The intended start date is a soon as possible, but before 31 December 2025 at the latest.

Closing date for applications: 30th of August 2025.