Photosynthesis Study Task Descriptions

The Photosynthesis Study kicked off on July 5, 2012 and concluded on July 31, 2014.

See also:  Org Chart

Tasks, Milestones, and Deliverables

Seven organizations from seven countries were involved in the FLEX Photosynthesis Study, necessitating an effective strategy for overall management and coordination of activities.  The study was divided into seven tasks and thirty-four workpackages, summarized here and detailed in the sections below.  Fourteen deliverables were scheduled.  Findings from the Photosynthesis Study formed the basis of advice and recommendations developed throughout the project, eventually culminating in the final package assembled under Task 7.

TASK 1.  Management and coordination of activities

Key aspects included in Task 1 were:  establishment of a study website to provide project updates and document sharing;  overall coordination and management of the study to meet the specified deliverables;  and provision of an effective interface between the Photosynthesis Study and other FLEX studies and campaign activities.  Further, it was important to keep the FLEX Mission Advisory Group (MAG) informed, in order to support its advisory role to ESA in the completion of the Phase A/B1 assessments.

TASK 2.  Data sets & model availability review:
                Model/module assessment, comparison, and gap analysis

Task 2 generated and quality-checked a database of coupled photosynthesis-fluorescence (or GPP-canopy fluorescence) data for model/module verification at different scales.  (The database itself contained the necessary input data to force the models/modules and the output data to calibrate and validate the individual model components or the canopy-level model as a whole.)  The database was then used to assess individual modules and to compare alternative modules whenever possible (alternative leaf-level A-SIF modules, for example).  The exercise also developed a gap analysis, highlighting processes not currently well-represented.  No ex-novo module development was planned for this stage.

This task also addressed interfacing of the various modules, their functionalities, and the compatibility of the associated basic data sets.  These activities resulted in the recommendation of a suitable model design in joint agreement with Task 3 (implementation).

TASK 3.  Model implementation, validation, sensitivity analysis and error quantification

Taking as inputs the modules designed and developed in Task 2, a full modular forward model was developed and implemented in Task 3, combining the modules and sub-modules available.  Potential limitations identified in Task 2 were addressed through new module developments or revisions of existing components, making possible the integration of modules with the corresponding interfaces.

TASK 4.  Analysis of F-GPP relationships

Task 4 was to explore by means of numerical simulations and from the results of previous field campaigns and studies how canopy level fluorescence as retrieved from the FLEX mission can be related to photosynthesis in the vegetation canopyThis Task was suspended at ESA's request before start-up and was not revived.

TASK 5.  Algorithm development based on models

The objective of Task 5 was the development of a Level 2 prototype algorithm that could derive measures of photosynthesis (represented by GPP or eventually by any other relevant parameter) from the observations obtained from the FLEX/S3 Tandem Mission and eventual auxiliary data (if needed).  The work of this task relied heavily on the work undertaken during the previous tasks.

TASK 6.  Fluorescence as an indicator of vegetation health and stress resilience

The updated database together with consideration of applicable information from the modelling Tasks (as they became available) was used to forecast the strength of the novel signal to detect carbon assimilative potential and/or vegetation stress.  Conclusions were developed about the CF signal's capacity to detect stress when the SIF is spectrally resolved.  The final goal of Task 6 was to outline the potential and (subsequently) the methodological concept for using the FLEX remotely-sensed sun-induced chlorophyll fluorescence signal as an indicator of vegetation carbon sink capacity, health status, and stress resilience.

TASK 7.  Conclusions and recommendations

This last task prepared and submitted the final deliverables to ESA.  (The deliverables from all of the previous tasks were used as inputs to create the Final Report, its Abstract, and the Executive Summary.)  The Final Presentation, which offers an overview of all the work done in the study and its findings, provided an opportunity to receive feedback from ESA.  Submission of the Technical Data Package containing all science and software deliverables completed the contractual requirements of the PS Study.

See also:  Org Chart

About the FLEX Photosynthesis Study...

This study targetted the linkage between solar-induced chlorophyll fluorescence and photosynthesis in terrestrial vegetation.  A dedicated photosynthesis model based on state-of-the-art existing modules was developed and implemented.  We also developed and tested a prototype algorithm that can derive photosynthesis from FLEX tandem mission measurements.  The Photosynthesis Study was part of the package of parallel study activities needed for assessment of the FLEX candidate mission.

For further information about the PS Study, click here.  To read or download the Final Report, click here.  To see a list of publications from the PS Study, click here.