Measuring and understanding solar-induced fluorescence as an indicator for actual photosynthesis and vegetation function
Proposers: Uwe Rascher and Alexander Damm
The European Space Agency (ESA) is currently implementing the FLEX (FLuoresence EXplorer) satellite mission concept, which will be launched as 8th Earth Explorer mission in 2024. The FLEX satellite will provide global measurements solar-induced fluorescence that is emitted by terrestrial and costal vegetation. FLEX will have a spatial resolution of 300 meters and will provide global maps of solar-induced fluorescence (SIF) and actual rates of photosynthesis. Active chlorophyll fluorescence measurements are well established in the laboratory and on the ground and various instruments are available that exploit the dynamics of the fluorescence signal to quantify actual rates of photosynthesis non-invasively. In the past years it became feasible to retrieve the fluorescence signal also passively from high-resolution ground, airborne and satellite spectrometers and to use this information to early detect vegetation stress and to constrain local, regional and global carbon fluxes. With this session we aim to discuss the knowledge and concepts how solar-induced fluorescence can be measured and used for GPP modelling and plant stress detection. We invite results that are based on experimental field campaigns, airborne and satellite sensors, and associated ground instrument. We aim to present the current knowledge and challenge to understand the different fluorescence signals of different plant functional groups, the diurnal and seasonal cycle of fluorescence dynamics and their link to dynamically changing photosynthetic rates, and the seasonal activation and deactivation of the photosynthetic machinery. In this session we invite contribution that provide conceptual frameworks and experimental evidence how solar-induced fluorescence can track acute environmental stresses and studies that aim to include the fluorescence signal in ecosystem and carbon flux modelling.
With this session we aim to collect the most recent advances in the field. We invite contributions where fluorescence data (collected from the ground, airborne or satellite level) are used to better understand the dynamics of vegetation photosynthesis and stress response. Talks may cover one of the following topics:
- Novel measurement concepts to quantify solar-induced fluorescence (SIF)
- Methods to retrieve SIF from high resolution spectral instrument
- Algorithms, such as RTMs, machine learning and hybrid methods, that help to better understand the mixing and scaling of solar-induced fluorescence from the leaf to the canopy
- Modelling studies that use SIF to constrain carbon and ecosystem fluxes
- Approaches, which exploit solar-induced fluorescence as an indicator for vegetation stress
- Studies that aim to understand the diurnal and seasonal dynamics of solar-induced fluorescence and vegetation functioning