The CriticalEarth Project
Several subsystems of the Earth, so-called tipping elements, may respond abruptly at critical future levels of anthropogenic forcing. It is paramount to identify safe operating spaces in terms of these critical forcing levels, in order to prevent harmful transitions to alternative, undesirable states of the Earth and its subsystems. The mechanisms leading to climate transitions are only partly understood, and reliable warning signals for forthcoming transitions are urgently needed. CriticalEarth addresses these questions in a joint effort of 19 European institutions, combining paleoclimatology, time series analysis, Earth system modelling of past and future climates, applied mathematics and specifically dynamical systems theory.

The CriticalEarth consortium consists of universities and private entities with Researchers who are leading experts on climate dynamics and applied mathematics. The research training is composed of an ambitious scientific programme flanked by essential training courses with ample opportunity for networking at workshops, conferences and shared secondments. In addition to training young Researchers for tomorrow's challenges, CriticalEarth will provide excellent research with impressive scientific and societal impact from day one.

Detailed task description

• The successful candidate will be an Early Research Scientist (ESR-6) within the CriticalEarth project and will focus on the development of new methods to calculate rare events in high-dimensional climate models. Probabilities of rare events, and in particular of transitions between different equilibrium states of a certain multi-stable stochastic system, are often very difficult to compute. Standard Monte Carlo methods, i.e. by computing a large number of samples, and then counting the number of observed transitions, are not feasible when probabilities are small. Therefore, specialized methods, such as Trajectory-Adaptive Multilevel Sampling (TAMS) have been developed. The idea behind these methods is similar: the algorithms try to push samples in the direction of the transition to make sure transitions actually occur, also for smaller sample sizes, while still being able to compute the transition probability. In this project, you will work on refining a recently developed TAMS variant for high-dimensional dynamical systems. The novel method will be applied to a hierarchy of climate models and focus on several tipping elements.
• The successful candidate will be an Early Research Scientist (ESR-7) within the CriticalEarth project and will focus on the behaviour of the climate system due to the interaction of several tipping elements. Linkages between tipping elements have been proposed but it remains difficult to quantify thresholds for the occurrence of cascading tipping behaviour. Only recently, coupled tipping elements have been investigated using two tipping elements, which are linearly and uni-directionally coupled. This has also been extended to networks of bistable systems which are bi-directionally coupled. In order to study the occurrence and processes causing the cascading behaviour in the climate system, three tracks will be followed: (i) extend current theory for low-dimensional climate models to include stochastic noise and non-autonomous effects,  (ii) couple intermediate complexity climate models of specific climate tipping elements as mentioned above and study the effect of the coupling on the bifurcation behaviour of the coupled system, and (iii) simulate cascading tipping phenomena in a CMIP6 coupled climate model (CESM2) and investigate the behaviour and the processes responsible.

We are looking for an ambitious and driven candidate who has:

• an MSc in physics, applied mathematics, meteorology, geosciences or a related field;
• experience in climate modelling (considered an advantage);
• a basic knowledge of (geophysical) fluid dynamics (considered an advantage);
• excellent skills in scientific programming and numerical / statistical analysis of simulated and observed data.

• the opportunity to work in and with a team of leading experts;
• a full-time position for 4 years;
• a full-time gross salary that starts at €2,395 and increases to €3,061 per month in the fourth year (scale P of the Collective Labour Agreement Dutch Universities (cao));
• benefits including 8% holiday bonus and 8.3% end-of-year bonus;
• a pension scheme, partially paid parental leave, and flexible employment conditions based on the Collective Labour Agreement Dutch Universities.

In addition to the employment conditions laid down in the cao for Dutch Universities, Utrecht University has a number of its own arrangements. For example, there are agreements on professional development, leave arrangements and sports. We also give you the opportunity to expand your terms of employment yourself via the Employment Conditions Selection Model. This is how we like to encourage you to continue to grow.
ore information about working at the Faculty of Science can be found here.

The Institute for Marine and Atmospheric Research Utrecht (IMAU) offers a unique research and teaching environment, in which the fundamentals of the climate system are studied. Research is organized in five themes: Atmospheric Dynamics, Atmospheric Physics and Chemistry, Coastal and Shelf Sea Dynamics, Ice and Climate and Oceans and Climate. In 2017, IMAU research quality and impact were qualified as 'world leading' by an international visitation committee. Currently, IMAU employs 18 faculty members and 10 support staff and some 15 Postdocs and 29 PhD students, and offers a friendly, open and international atmosphere.

At the Faculty of Science there are 6 departments to make a fundamental connection with: Biology, Chemistry, Information and Computing Sciences, Mathematics, Pharmaceutical Sciences and Physics. Each of these is made up of distinct institutes which work together to focus on answering some of humanity’s most pressing problems. More fundamental still are the individual research groups – the building blocks of our ambitious scientific projects.

Utrecht University is a friendly and ambitious university at the heart of an ancient city. We love to welcome new scientists to our city – a thriving cultural hub that is consistently rated as one of the world’s happiest cities. We are renowned for our innovative interdisciplinary research and our emphasis on inspirational research and excellent education. We are equally well-known for our familiar atmosphere and the can-do attitude of our people. This fundamental connection attracts Researchers, Professors and PhD candidates from all over the globe, making both the university and the Faculty of Science a vibrant international and wonderfully diverse community.