PhD offer Understanding the relation between photosynthesis and sun

Work environment, missions and activities

Photosynthesis is unfortunately not measurable directly on scales greater than a single plant. The lack of predictability of future photosynthesis is thus one of the largest uncertainties in climate projections (IPCC, 2021).

Chlorophyll fluorescence is an afterglow of photosynthesis and hence tightly linked to Gross Primary Productivity (GPP). Sun-induced chlorophyll fluorescence (SIF) has become the quasi-reference in studies of the carbon cycle and the response of GPP to environmental cues, on the simple basis that remotely-sensed SIF from satellites correlates well with GPP estimated on eddy covariance flux towers on a weekly to monthly scale. Several satellite missions that target SIF are to be launched in the near future such as ESA’s FLEX mission scheduled for 2026. Large-scale GPP can otherwise not be measured directly and not be determined from satellite observations. However, the correlation between GPP and SIF breaks down completely for daily and diurnal observations and the simplified concepts to describe SIF from forest canopies are not valid anymore on such short timescales.

Objective: The PhD project will use model-data fusion to understand mechanistically the observed signal of SIF above forest canopies and its link with GPP of the ecosystem. It will measure for the first time active and passive SIF within a forest canopy, making it possible to describe mechanistically other loss processes in the photosynthesis apparatus.

Training and skills

Master's degree/Engineering degree

We are seeking a motivated candidate that likes to combine biology with physics, i.e. combining biochemical modelling at the leaf level with physical modelling at the canopy scale. All quantitative analyses will use mechanistic modelling with MuSICA so strong computer skills and an aptitude for physics will be required. As the project uses model-data fusion, active participation in two measurement campaigns will be essential. There should be an interest in research related to climate change and an affinity to work with international partners.

How to apply

To apply, please send a cover letter, a CV, the transcript of grades of the master (or of the 3 years of engineering school), a contact information of an academic reference, as well as a résumé (300 words) of the master topic (or of the end-of-study internship) to Matthias Cuntz – matthias.cuntz@inrae.fr

Location

The thesis will take place for three years at the UMR Silva on the campus of INRAE near Nancy (54280 Champenoux) from autumn 2026 onwards.