PhD: Coupling the biological pump to past changes in the AMOC

The Department of Earth Sciences is looking for a highly motivated PhD candidate with an MSc background in Earth Sciences, Marine Sciences or other appropriate field. You will work on the project ‘Coupling biological pump changes to variations in the Atlantic Meridional Overturning Circulation (AMOC) during rapid climate transitions’.

Your job
The AMOC transports warm saline waters from the tropics to the high northern latitudes of the North Atlantic where they cool and sink. This part of the density-driven global “conveyor belt” may be losing its strength due to ongoing global warming, with potential large-scale climate repercussions. Even more so since the AMOC brings CO2 from the surface to the deep ocean during deepwater formation (physical pump), and variations in the AMOC strength will change the ability of the ocean to absorb CO2. The magnitude of this impact and the processes involved remain however difficult to predict. Also in the past, the strength of the AMOC varied and abrupt shifts between cold and warm periods have been recorded in marine sediments on geological timescales. The North Atlantic Ocean is also a key region for carbon sequestration by the biological carbon pump. Hence, the transfer of both organic carbon and inorganic carbon from the surface to the deep ocean is locally promoted. The aim of the project is to investigate interaction between changes in the AMOC and the physical and biological pumps during rapid climate transitions (e.g., the last glacial period and Holocene) using sediment records. Our data will be used in marine carbon cycle models to predict (future) carbon sequestration upon changes in the AMOC strength.

During this four-year PhD project, you will apply a multiproxy (biogeochemical and micropaleontological/palynological) approach to sediment records from selected locations in the North Atlantic collected along a present-day temperature and salinity latitudinal transect. You will reconstruct surface and deep-water temperatures and salinity, and the (efficiency) of the organic and inorganic biological carbon pump via proxies indicative of primary productivity, CO2/pH in a surface deep-water gradient at times of known major past climate shifts and AMOC changes at decadal to millennial timescales. This project may include participation in seagoing expeditions.

This project is part of the 10-year EMBRACER research programme funded by the Dutch Research Council (NWO). At EMBRACER, we work at the very frontiers of knowledge on climate change, earth’s climate system and climate feedbacks. The programme brings together a wide range of world-leading climate experts with the aim to address existing uncertainties about climate feedbacks at the boundaries between oceans, land, ice, and atmosphere. Our interdisciplinary approach and state-of-the-art infrastructure will bring us forward in our understanding of the impact of climate feedbacks emerging over the next decades to centuries.

A personalised training programme will be set up, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes following courses/workshops as well as training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University.

The project leader and daily supervisor will be Dr Francesca Sangiorgi and close collaboration in the project will be with Prof. Gert-Jan Reichart Dr Martin Ziegler, and Dr Lennart de Nooijer. Multiple others will be involved for specific aspects of the project. Foreseeable international collaborators include Profs. Stijn de Schepper and Ulysses Ninnemann (University of Bergen, Norway).

We seek an independent, enthusiastic and highly motivated team player who has a keen interest in marine biogeochemistry, micropaleontology/palynology, and paleoceanography and who is eager to perform multiproxy research in a collaborative (international) group. You have completed your MSc degree in Earth Sciences, Marine Sciences or a related discipline by the time the position starts. Furthermore, you have:

• experience and affinity with paleoceanography and/or marine palynology/micropaleontology, and/or biogeochemistry, and marine research
• passion for chemical laboratory work and data analysis
• an open, communicative and collaborative attitude
• willingness and ability to join sea-going expeditions should occasions arise and to spend short visits to other universities and research institutes in the Netherlands and abroad.
• excellent communication skills

Due to the international character of our research, proficiency in spoken and written English is essential. We highly encourage applicants from all members of our community and of diverse backgrounds to join us.

• A position for 1 year, with an extension to a total of four years upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period;
• a working week of 36-40 hours and a gross monthly salary between €2.901 and €3.707 in the case of full-time employment (salary scale P under the Collective Labour Agreement for Dutch Universities (CAO NU));
• 8% holiday pay and 8.3% year-end bonus;
• a pension scheme, partially paid parental leave and flexible terms of employment based on the CAO NU.

In addition to the terms of employment laid down in the CAO NU, Utrecht University has a number of schemes and facilities of its own for employees. This includes schemes facilitating professional development, leave schemes and schemes for sports and cultural activities, as well as discounts on software and other IT products. We also offer access to additional employee benefits through our Terms of Employment Options Model. In this way, we encourage our employees to continue to invest in their growth. For more information, please visit Working at Utrecht University.

A better future for everyone. This ambition motivates our scientists in executing their leading research and inspiring teaching. At Utrecht University, the various disciplines collaborate intensively towards major strategic themes. Our focus is on Dynamics of Youth, Institutions for Open Societies, Life Sciences and Pathways to Sustainability. Sharing science, shaping tomorrow.

Utrecht University’s Faculty of Geosciences studies the Earth: from the Earth’s core to its surface, including man’s spatial and material utilisation of the Earth – always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development.

The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. Our key research themes are Earth & Planetary Processes, Sustainable Use of the Subsurface, Planetary Health & Environment, and Climate & Life. The department hosts a highly international tenured staff of over 50 scientists and more than 110 PhD students and postdoctoral researchers. We house or have access to a wide variety of world-class laboratories, among which are UU’s Electron Microscopy Centre, the Geolab, and the Earth Simulation Lab. We also have excellent High- Performance Computing facilities.

About Utrecht
The department and its facilities are located at Utrecht Science Park. Utrecht is the fourth largest city in the Netherlands with a population of nearly 360,000 and forms a hub in the middle of the country. Its historical city centre and its modern central station can easily be reached from the Science Park by public transport or by a 15-minute bicycle ride. Utrecht boasts beautiful canals with extraordinary wharf cellars housing cafés and terraces by the water, as well as a broad variety of shops and boutiques.