PhD position - Earth System Science within the HDS-LEE graduate school

In the coming decades, climate change and shifts in land use will have a significant impact on the productivity of terrestrial ecosystems in terms of the services they provide (food, feed, fiber, energy), as well as on the challenges society must address. At the Institute of Bio- and Geosciences – Agrosphere (IBG-3), we develop solutions to safeguard ecosystem services based on an improved understanding of hydrological and biogeochemical processes in terrestrial systems. Our focus is on agricultural and forest systems, which are coming under increasing pressure due to global change. Innovative observation technologies are combined with laboratory experiments and modeling to investigate and predict terrestrial processes across scales (from the pore scale through the field scale to the continental scale), thereby contributing to the sustainable use of the natural resources water, soil, and atmosphere.

Your Job

The PhD position is offered in the context of the HDS-LEE graduate school. We are looking for a highly motivated PhD candidate to join our world-leading research program in Earth System modelling and improving Earth System Modeling by better merging of measurement data and model simulations.

This PhD project focuses on improving how we estimate key parameters in land-surface and ecosystem models, which are essential for understanding climate change impacts. The work involves reviewing existing modeling and model–data fusion techniques, and developing faster, machine-learning–based tools that can stand in for slow model simulations. These tools will be used to test how model parameters influence results and to make parameter estimation more efficient. The project will apply and evaluate these new methods at different sites and time periods, compare them with established approaches, and finally demonstrate their potential in a Europe-wide ecosystem reanalysis. The outcomes will include open-source software, scientific publications, and a PhD thesis.

Your tasks within this framework in detail:

Conduct a literature review on modern techniques for combining models with observational data, with a focus on innovative parameter-testing and hybrid modelling approaches.
Gain a solid understanding of land-surface modelling and the land-surface model used in the project.
Develop simplified, fast-running model surrogates using machine-learning methods to replace very time-intensive simulations.
Design an efficient training strategy for these machine-learning tools, making use of existing model simulations and actively selecting new simulations where needed.
Build and test a model “emulator” that can quickly explore how changes in model parameters affect model behaviour, and validate it using independent sites and time periods.
Use the newly developed tools to estimate key ecosystem and land-surface parameters, and compare the results against existing model–data fusion methods.
Apply the improved parameter-estimation techniques in a larger-scale setting to demonstrate their potential for ecosystem reanalysis.
Prepare scientific publications and present results at conferences.
Publish the developed software openly with documentation.

Your Profile

A Masters degree with a strong academic background in mathematics, computer science and earth science/engineering, or a related field
Proficiency in at least one programming language (Python, Matlab, R, C++, Julia, …)
Genuine interest in data science and earth sciences
Good analytical skills with a sound understanding of data evaluation
Kowledge of numerical simulation, for example with land surface or hydrological models
Good organisational skills and ability to work both independently and collaboratively
Effective communication skills and an interest in contributing to a highly international and interdisciplinary team
Motivation for academic development, supported by bachelor’s and master’s transcripts and two reference letters
Working proficiency of written and spoken English with extensive vocabulary is required for daily communication and professional contexts (at least B2 level according to the ), supported by a certificate confirming the language level (TOEFL or equivalent or excemption required).
Knowledge of German is beneficial

Our Benefits for You

We work on the very latest issues that impact our society and are offering you the chance to actively help in shaping the change! This HDS-LEE PhD position will be located at Forschungszentrum Jülich and RWTH Aachen. We offer ideal conditions for you to complete your doctoral degree:

Team & Environment: You will work in a motivated team with an international and interdisciplinary focus – at one of the largest research institutions in Europe. Your working place is at Forschungszentrum Julich (group of Prof. H. Hendricks-Franssen); regular exchange with RWTH Aachen (group of Prof. J. Kowalski) is planned.
Research & Infrastructure: You will have access to excellent scientific and technical facilities for your work. PhD students are encouraged to attend international conferences and a three months research stay abroad with a cooperating partner is possible.
Attendance in our Graduate School: Unique (including data science courses, soft skill courses and annual retreats)
Networking & Exchange: You will participate in (international) conferences and project meetings and actively build your scientific network
Supervision & Support: We will accompany your doctoral studies with continuous, expert guidance from your academic supervisor
Work-life balance: We offer flexible working hours to help you balance your professional and personal life. You also have the option of flexible working (in terms of location), which is generally possible after consultation and in line with upcoming tasks and (on-site) appointments
Annual Leave: You get 30 days of annual leave
Knowledge & Development: Your professional development is important to us – we support you specifically and individually e.g., through training and networking opportunities specifically for doctoral candidates
Health & well-being: Your health is important to us. You can look forward to a comprehensive company health management programme with a wide range of options, including a beach volleyball court, running groups, yoga classes and much more. In addition, our company medical service and an experienced social counselling team are available to assist you on site
Campus experience: Our research campus in the countryside creates ideal conditions for collegial exchange and sporting activities right on site. Our cafeteria offers a wide range of options—you can enjoy a relaxing lunch break with a lake view
Successful start: It is important to us that you quickly settle into the team and are given structured training for your tasks. We also support you from the very beginning and make your start easier with our
Fair remuneration: Depending on your qualifications and assigned responsibilities, you will be classified according to pay group 13 (75%) of the TVöD-Bund. In addition to the basic salary, there is an additional year-end bonus under the collective pay agreement amounting to 60% All information about the TVöD-Bund collective agreement can be found on the (pay scale table on page 66 ff. of the PDF download)
Perspective: The position is initially for a fixed term of 3 years but with the prospect of longer-term employment or
Fixed-term: The position is limited to 3 years
Support for international employees: Our International Advisory Service makes it easier for international employees to get started

In addition to exciting tasks and a collegial working environment, we offer you much more:

We welcome applications from people with diverse backgrounds, e.g. in terms of age, gender, disability, sexual orientation / identity, and social, ethnic and religious origin. A diverse and inclusive working environment with equal opportunities in which everyone can realize their potential is important to us.

The following links provide further information on diversity and equal opportunities: and on specific support options:

Place of Employment: Jülich

**Start Date:**To the next possible date

Salary: Pay group 13 (75%) TVöD-Bund

Application Deadline: The position will be advertised until it is successfully filled.