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FED-tWIN Postdoctoral Researcher in the Evaluation of Atmospheric Composition in Chemistry Climate Models using Satellite Datasets (m/f/x)



Start date
Deadline for applications
Job title description

The Chemical Weather Unit of the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) and the Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing Group of the Université Libre de Bruxelles (ULB) are looking for a highly motivated and skilled Postdoctoral Researcher to join their teams.

Statute: Contractual
Start date: October 1, 2023
Deadline for applications: June 2, 2023

Division, context

The Chemical Weather Unit of the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) and the Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing Group of the Université Libre de Bruxelles (ULB) look for a highly motivated and skilled Postdoctoral Researcher to join their teams. This recruitment is part of the research profile Prf-2021R-045 BeCCM-O3#2 – “Building a benchmarking service for Chemistry-Climate Models with sustainable satellite records of ozone, its radiative effects, and related tracers” within the framework of FED-tWIN, the Belgian Programme of sustainable research cooperation between the Federal Scientific Institutes and the universities. FED-tWIN research profiles are jointly elaborated by a FSI and a university, to be implemented by a post-doctoral researcher who is employed half-time at the FSI and half-time at the university.

BIRA-IASB is a Belgian Federal Scientific Institution conducting research and providing services in space aeronomy i.e., the physics and chemistry of Earth’s atmosphere and other planets, and outer space. The Chemical Weather Unit studies the chemical composition of the middle atmosphere and contributes to the improvement of short-term forecasts and long-term projections by chemistry- climate models.

The “Spectroscopy, QUantum chemistry and Atmospheric REmote Sensing” (SQUARES) laboratory of ULB has a strong expertise on the sounding of atmospheric composition by satellites. It participates to remote sensing satellite missions, to the exploitation of their results, and performs ground-based validation measurements. Specifically, the group has built a leadership in the field of infrared atmospheric radiative transfer, exploiting, in the last 15 years, the measurements of the IASI sounders onboard Metop satellites for atmospheric composition and climate applications. The two teams have had a fruitful collaboration during the last 5 years.

With this joint research profile, we wish to deepen this collaboration between the two groups and address critical challenges to the evaluation of atmospheric composition in chemistry-climate models using satellite datasets. With the guidance and support from both groups, the postdoctoral researcher will pursue innovative and interdisciplinary research relying on satellite products as well as on numerical modelling of the atmospheric climate and composition.

For further information on the activities of these two groups, please see:


Description of the research profile

The position to be held consists of a half-time position at BIRA-IASB and a half-time position at ULB. The candidate applies for both positions at once and it is not possible to apply for one position only. You will be part of the Chemical Weather Unit of BIRA-IASB and the SQUARES laboratory of ULB.

The main objective of this research profile is to build a benchmarking activity for the atmospheric components in Chemistry-Climate Models (CCMs) using three recent satellite datasets that focus on ozone and a few related tracers. This will guide the modelers in improving the processes that drive stratospheric composition in their CCMs, thanks to creative analyses of the O3, N2O and HCl variabilities and the attribution of a grading score for each investigated diagnostic.
The three satellite datasets are FORLI-O3, retrieved by ULB/SQUARES from IASI (2007-2023+); BRAM, a BIRA-IASB reanalysis of Microwave Limb Sounder observations (2004-present); and GOP-ECV, a homogenized dataset that is being consolidated from European UV-Visible instruments (1995- 2023+). The scientist will exploit the N2O and HCl datasets in BRAM to evaluate the representation in CCMs of the primary causes of long-term changes in ozone i.e., the changing Brewer-Dobson Circulation (BDC) and chlorine loading.
Quantitative model evaluation will be built on the methods developed by BIRA-IASB’s contributions to the evaluation of the Copernicus Atmosphere Monitoring Service (CAMS) by deriving process- oriented diagnostics of the interannual variations of N2O, HCl and ozone. Dedicated regression analyses will be performed on both the observed and modelled datasets to benchmark the variabilities of these species in the CCMs. The results obtained from each reference dataset will be compared to those obtained from modelled datasets considering their different coverages, samplings, and vertical resolutions.
In the longer term, the scientist will study some CCM sensitivity tests to investigate further the causes of the modelled ozone trend biases; the changing amounts of tropospheric ozone, using tropospheric columns from FORLI-O3 and possibly GOP-ECV as reference datasets; and the role of ozone as a near- term climate forcer, thanks to a novel dataset from IASI: the ozone Long-Wave Radiative Effect (O3LWRE).


At BIRA-IASB, you will manage the model datasets and process them to allow consistent comparisons with the satellite datasets; apply to these datasets the same statistical regression tools which are developed at ULB/SQUARES for the observational datasets and adapted for tropospheric and stratospheric O3 studies; evaluate the representation of the different modes of ozone variations in the selected models to benchmark; configure and run CCM sensitivity tests to investigate the relationships between modelled processes and sources of ozone variability; identify and retrieve the model datasets to include in the study of tropospheric ozone; apply to these datasets the same methods as developed for stratospheric ozone.

At ULB, you will strengthen the exploitation and the valorization of the in-house FORLI-O3 and O3LWRE products from the three IASI satellite sounders and extend these to the next generation of IASI instruments; generate level-3 FORLI-O3 datasets that will be directly integrated in BeCCM-O3#2; extend and develop statistical regression tools to address the scientific questions of this profile and apply them to the selected observational datasets for the benchmark of CCMs; extend the expertise acquired by the group in the interpretation of the IASI O3 observations, in particular in terms of natural sources of ozone variations and anthropogenic trends; help in consolidating the development of new/updated FORLI-O3 products; explore the potential synergy/consistency between FORLI-O3 and the two other satellite datasets used in BeCCM-O3#2.

At both institutions, you will supervise and support Master and PhD students and contribute to the preparation and management of new research projects; have a collaborative spirit and liaise with collaborators; organize and troubleshoot your work independently, document it thoroughly and communicate results and experiences with the team in a transparent and professional manner.

Required competences

We are looking for a highly motivated, well-organized, and dynamic candidate with a high level of independence and creative thinking. The successful candidate should:

  • hold a PhD degree in Physics, Chemistry or Applied Sciences obtained at the earliest 12 years prior to the submission date of the job application. The 12-year period is extended by one year for each maternity, parental and adoption leave of the candidate and for each long-term sick leave of the candidate or his/her immediate family;
  • have at least 3 years experience as postdoctoral fellow in a relevant field, in particular in remote sensing and/or modelling of stratospheric composition;
  • have a good publication track record with several first author publications in highly-ranked international scientific journals and oral presentations at international conferences;
  • have a very good knowledge of widely used data processing and analysis tools in environmental sciences (Python, Matlab, IDL) and with scientific data formats (HDF, NetCdf);
  • be able to work independently and in a team, as well as in an international environment;
  • be eager to learn new techniques and show keen interest and curiosity driven approach to scientific questions;
  • be able to guide PhD students and coordinate the projects between the two teams;
  • have excellent oral and written English communication skills, a good knowledge of French or Dutch is an asset;
  • have experience in writing research proposals, in working with deadlines and being involved simultaneously in multiple projects.


Specific expertise in any or more of the following fields is a bonus:

  • satellite datasets of atmospheric composition and their validation, especially ozone;
  • Atmospheric radiative transfer and inverse methods
  • regression analyses;
  • processing of output datasets by Chemistry-Climate Models, preferably those made for the Climate Model Intercomparison Project.
Offer and benefits
  • A contractual position of indeterminate duration, with simultaneous 50% appointment at BIRA-IASB and 50% appointment at ULB;
  • A stimulating research work environment where quality, professionalism and team spirit are encouraged;
  • At BIRA-IASB, the salary will follow federal regulations for the scientific career in the SW2 scale, with possibility to acquire a bilingualism bonus
  • At ULB, the salary will be that of post-doctoral researcher at scale 530;
  • Access to state-of-the-art infrastructure at BIRA-IASB and ULB;
  • Extra-legal benefits are offered both at BIRA-IASB and ULB;
  • Flexible schedule and possibility to work partly from home;
  • Refund of commuting expenses when using public transportation or bicycle;
  • Access to special advantages arranged for employees of the federal scientific institutions and ULB (e.g. possibility to follow trainings, childcare, etc.);
  • The opportunity to interact with several world-class investigators at both institutions, as well as in Europe and abroad (through an established network and research consortia)
  • All relevant work experience (public/private sector) will be considered when determining seniority.


Place of employment
  • ULB , 50 avenue F. D. Roosevelt 1050 Brussels, Belgium on the "Solbosch" campus
  • Royal Belgian Institute for Space Aeronomy, Avenue Circulaire 3, 1180 Uccle, Belgium

The selection committee will review all of the applications as soon as possible after the application deadline. As soon as a decision has been made, the selected candidates will be invited for an interview either in person or by teleconference.

Both BIRA-IASB and ULB encourage diversity and attach great importance to an inclusive working environment and equal opportunities, regardless of gender identity, disability, race, ethnicity, religion or belief, sexual orientation or age. BIRA-IASB has published its Gender Equality Plan. We encourage people from diverse backgrounds and with diverse characteristics to apply.

If you have any questions relating to accessibility or support, please contact us at hr-ae (at) aeronomie (dot) be and/or drh (at) ulb (dot) be .


Please send your application by e-mail until Friday June 2, 2023 (by midnight Brussels time) to Simon (dot) Chabrillat (at) aeronomie (dot) be and Pierre (dot) Coheur (at) ulb (dot) be with hr-ae (at) aeronomie (dot) be in cc.

This e-mail application should mention reference D34-FEDTWIN- Prf-2021R-045 in the subject line and have the following attached documents:

  1. your motivation letter,
  2. your academic CV including a complete publication list,
  3. a description of your five most important publications or realizations,
  4. copies of your PhD diploma. If you have a foreign diploma in a language other than our national languages (Dutch, French or German) or English, you must attach a corresponding translation into one of the above languages.
More about BIRA-IASB

The Royal Belgian Institute for Space Aeronomy (BIRA-IASB) is a Belgian Federal Scientific Institute.

Since its founding in 1964, BIRA-IASB has been conducting research and providing public services in space aeronomy, i.e. the physics and chemistry of Earth's atmosphere and other planets, and outer space.

Our scientists use instruments on the ground, in the air, on board balloons or in space and computer models.