Postdoc: Ocean Acidification & the Marine Phosphorus Cycle

The NWO-funded PHOSFLUX project aims to shed light on these unknowns, by quantifying the role of CaCO3 fluxes and acidification in global marine P cycling through a combination of field work in the North Atlantic Ocean, laboratory experiments and numerical modelling. A scientific cruise with our research vessel Pelagia will allow us to investigate CaCO3 – P interactions in the field. Through controlled lab experiments, we will dive deeper into the underlying chemical and mineralogical processes, to eventually capture them in physical-chemical models that predict the impact of acidification on marine P cycling.

The PHOSFLUX project is a collaboration between the NIOZ (dr. Peter Kraal) and Utrecht University (UU; prof. dr. Mariëtte Wolthers), combining unique sea-going and on-shore experimentation with advanced analytical tools to understand mineral-water interactions from microscopic to ocean-basin scale. Besides PI’s Kraal and Wolthers, the PHOSFLUX team consists of a NIOZ-based PhD student performing experiments and analyses, and a UU-based postdoctoral researcher who focuses on modelling the CaCO3 – P interactions.

As postdoctoral researcher within PHOSFLUX, your role is to model P dynamics in sinking and deposited marine snow in relation to changing environmental conditions in the water column. To achieve this, you will create a reactive-transport model for P dynamics that will include processes such as CaCO3 dissolution, organic matter decomposition and adsorption/incorporation of PO4 into solid phases of marine snow. You will test the performance of your model by simulating experimental and field data in collaboration with the PHOSFLUX PhD student.

Postdoc: Machine learning for wind flow prediction in coastal dunes

In this 2-year postdoc position, you will use numerical modelling and machine learning techniques to increase the accuracy of coastal dune models. As a result, your project will inform and enhance decision-making in coastal dune management.

The ultimate goal of this project is to build a surrogate wind field model that can feed accurate wind field predictions into numerical coastal dune models. You will start by evaluating current wind field predictions from the coastal dune model AeoLiS by comparing model output with existing field measurements and/or Computational Fluid Dynamics (CFD) simulations. Specifically, you will assess where simplified assumptions in the model fall short. You will then train a machine learning model (such as PySR or neural networks) on CFD data to develop a fast, data-driven wind field predictor. You will combine this surrogate model with AeoLiS and evaluate the accuracy of the new model setup by applying it to existing case studies. Where needed, you will contribute to field data collection to support model validation. You will share your results in stakeholder meetings, scientific conferences, and academic journals.

Junior Research Assistant in Research and Reproducibility

The Psychology of Political Behavior Studies (PPBS; ppbs.science) is a longitudinal research programme examining political attitudes, identities, behaviour, and psychological constructs across multiple survey waves, samples, panel providers, and countries. PPBS maintains linked codebooks, data-processing workflows, reproducible reports, a public website, and shared research and project-management infrastructure.

As Senior Research Assistant in Research Operations and Reproducibility, you will ensure that this infrastructure is organised, documented, reproducible, and moving forward. You will work under the direction of Dr Flavio Azevedo and Jasmin Haggemann. You will independently own the technical operation of the pipeline, while scientific, measurement, ethical, and strategic decisions remain with the supervisors and relevant PPBS researchers.

Your core tasks include:

• running, maintaining, debugging, documenting, and incrementally improving PPBS workflows in R and R Markdown or Quarto;
• managing the progression from raw survey exports to cleaned, labelled, processed, validated, and versioned analysis-ready datasets without compromising source-data integrity;
• maintaining reproducible construct reports with descriptive statistics, scale reliability, tables, figures, and transparent analytical documentation;
• implementing and checking variable recoding, value labels, missing-data rules, reverse scoring, derived variables, composite scores, and cross-wave harmonisation;
• generating and maintaining empirical codebooks, data dictionaries, metadata outputs, construct specifications, and validation checks;
• maintaining the PPBS website repository and publication workflow in GitHub, including routine content and report updates and diagnosis of build or deployment problems;
• organising research files and documentation across Dropbox, Google Drive, and GitHub, with clear provenance, naming, versioning, access, and release status;
  preparing meeting agendas and minutes, recording decisions and dependencies, maintaining action trackers, coordinating hand-offs, and following up with contributors; and
• identifying operational and reproducibility risks early, proposing proportionate solutions, and escalating decisions that require scientific or managerial authority.

Because the appointment is short and part-time, the immediate priority is reliable pipeline and report ownership, followed by operational coordination and routine website maintenance. Major software redevelopment or independent statistical research is outside the role unless separately agreed and resourced.

Coordinerend Contentredacteur

Je coördineert multimediale contentproducties en campagnes van idee tot publicatie. Je werkt aan gerichte content voor de vier gedefinieerde doelgroepen: studiekiezers, studenten, medewerkers en algemeen breder publiek. Vanuit de strategische thema’s van de Universiteit Utrecht zorg je er samen met collega’s voor dat de content aansluit bij deze doelgroepen.

• Je verzorgt eindredactie bij de aan jou toegewezen content en ziet toe op merkconsistentie en kwaliteit.
• Je voert regie op de planning van campagnes en projecten en bewaakt deadlines.
• Je vertaalt contentstrategie naar aansprekende formats en redactionele vormen die passen bij de doelgroep en het kanaal.
• Je zorgt voor samenhang tussen verschillende contentinitiatieven en signaleert kansen om ze slim te combineren.
• Je schrijft en redigeert teksten; van pakkende titels en social captions tot artikelen.
• Je maakt zelfstandig visuele en multimediale content en schakelt voor de complexere producties specialistische collega’s in.
• Je optimaliseert contentprocessen en draagt bij aan efficiënte workflows, aanpak en samenwerking.

Je maakt deel uit van het team Content en Digital, een team van ongeveer twintig professionals. Het team voert de regie op merkcontent zoals video’s, explainers, artikelen, podcasts, live streaming en social content en digitale kanalen zoals de corporate website UU.nl, intranet, social media, nieuwsbrieven en narrowcasting. Je werkt onder andere samen met een hoofdredacteur, channel managers, contentstrategen, data-analisten, grafisch vormgevers, een projectmanager, redacteuren en AV-makers. Met positionerende content en campagnes stellen we de directie Communicatie in staat om de merk- en communicatiedoelstellingen van de Universiteit Utrecht te realiseren.

Medewerker Salarisadministratie

Je verwerkt salarismutaties en controleert gegevens in SAP op juistheid en volledigheid. Je beantwoordt vragen van collega’s over de salarisverwerking en past wet- en regelgeving correct toe. Daarnaast draag je bij aan het verbeteren en automatiseren van onze HR- en salarisprocessen.

Jouw werkzaamheden:

• verwerken van salarismutaties in SAP;
• controleren van gegevens op juistheid en volledigheid;
• uitvoeren van proefberekeningen;
• beantwoorden van vragen over salarisverwerking van collega’s en leidinggevenden;
• toepassen van wet- en regelgeving, cao’s en interne afspraken;
• opstellen van rapportages;
• bijdragen aan de digitalisering en automatisering van HR- en salarisprocessen;
• signaleren van knelpunten in processen en aandragen van verbetervoorstellen.