Evolution of the dry season in Central Africa during the Holocene and its implications for forest structure, water, and carbon fluxes (M/F)

Job Description

Missions

In close collaboration with the partners of the ANR DYSCATTI project, you will be responsible for analyzing the evolution of the dry season in Central Africa during the Holocene. Your work will be based on simulations covering the last 6,000 years, conducted using the IPSL model, which integrates a vegetation dynamics module and the carbon cycle. The challenge is to provide a temporal depth to the understanding of the driving mechanisms of Saharan-origin dry incursions in the northern part of the Congolese forest, as well as their impact on the forest's structure (e.g., changes in Plant Functional Types, PFTs) and functioning (water and carbon fluxes).
Using statistical analyses of event-type classification, contingencies, and causality, the objective will be to determine which characteristics of the region's semi-annual water cycle most significantly affected the natural evolution of the tropical forest during the Holocene, and to identify the environmental conditions most conducive to dry incursions. Particular emphasis will be placed on the role of Atlantic Ocean variability and the interactions between the hydrological and carbon cycles at the scale of the Congolese forest and its regional specificities.
The results will complement the approaches of other partners based on in situ data, satellite imagery, and simulations of current and future climates, aiming to develop an integrated vision of the dry season across the Holocene-Anthropocene continuum, from intra-seasonal variability to centennial scales. Definitions and the main characteristics of dry incursions will be provided by project partners specializing in the meteorology and hydrology of the study region. Ultimately, the results will lead to a better understanding of the vulnerability of this under-studied tropical forest to climatic factors.

Activity

• Analysis of the evolution of the dry season and the variability or extreme events that occurred over the last 6,000 years.
• Estimation of the tropical forest's vulnerability to climatic factors, initially excluding direct human impact on the forest to establish specific climate vulnerability indicators.
• Implementation of simulations to test hypotheses regarding the links between dry incursions and dry season characteristics, based on simulated variability events during the Holocene and test simulations to estimate the role of human activity relative to natural factors.
• Comparison of simulation results with available Holocene paleoclimate data and the recent climate evolution studied by other partners.
• Publication of one or more articles on the postdoctoral research topic, in collaboration with other project partners for result syntheses or cross-analyses between the past, present, and future.

Your Profil

Skills

• PhD in Climate Modeling, climate variability, or interactions between climate and biogeochemical cycles (with a particular interest in vegetation).
• Proven ability to work effectively in a team and the capacity to operate at the interface between multiple laboratories and diverse methodological approaches.
• Strong proactive mindset, creativity, autonomy, and the ability to communicate and report on research progress effectively.
• Proficiency in climate modeling and the execution of simulations, OR expertise in the analysis of large datasets (Big Data) with the ability to work on a national High-Performance Computing (HPC) center.
• Strong commitment to the dissemination of results and the writing of high-impact scientific publications.
• Proficiency in English B2 to C2 and French A2 to C2

Your Work Environment

The DYSCATTI project was initiated following observations from two meteorological stations established in northern the Republic of the Congo in 2016. These data reveal that during the boreal winter, atmospheric drought is pronounced, with extremely dry air episodes lasting up to three weeks. The dry season in this region remains under-studied, despite being a determining factor in the past and present extent, as well as the overall functioning, of African forest ecosystems. The postdoctoral researcher will contribute to Work Packages (WP) 4 and 5 of the ANR DYSCATTI project. This position will be held in partnership with the Biogeosciences Laboratory at Bourgogne Europe University (Dijon) and will involve regular collaboration with the entire consortium.
The work will be conducted within the MERMAID team at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE). The team specializes in climate and biogeochemical cycle modeling, as well as simulations dedicated to the study of climate variability and both anthropogenic and natural changes, specifically through transient simulations of the Holocene. The team is deeply involved in the modeling center of the Institut Pierre Simon Laplace (IPSL), which coordinates the development of the IPSL climate model.
Located on the Paris-Saclay campus, the LSCE is a joint research unit (UMR) involving the CNRS, the CEA, and UVSQ. At the CNRS level, its activities fall under the Institut des Sciences de l'Univers (ISU). The LSCE hosts a "Climate Modeling and Cycles" theme comprising four teams, including the MERMAID team. This theme contributes to the IPSL modeling efforts and develops research on climate and paleoclimates, as well as the links between climate and biogeochemical cycles (aerosols, chemistry, carbon cycle, etc.). This allows for the study of complex interactions within the climate system and supports research addressing climate change mitigation and adaptation. The theme also brings together specialists in statistical methods focused on the detection and attribution of climate change, as well as climate extremes and rare events.
Contract Details
This postdoctoral position is offered for a duration of two years. The successful candidate will be based at the LSCE under the supervision of Pascale Braconnot, Olivier Marti, and Julien Crétat (Bourgogne Europe University). The postdoctoral topic, and the DYSCATTI project more broadly, addresses a critical and timely issue: the future of the water and carbon cycles and the evolution of forests along the northern fringe of Central Africa—a region that remains under-studied despite its recognized vulnerability to ongoing climate change. The project's results will feed into the water cycle axis of the "Lighthouse Activity Safe Landing Climate" within the global climate research program.

Constraints and risks

N/A

Compensation and benefits

Compensation

between 3 131€ à 4 341€ brut € brutto

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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