Introduction
The ESA EO Science Strategy Foundation Study (SSFS) is generating the evidence to underpin the next EO Science Strategy due to be released in 2024.
As part of this work the study team is generating a set of “Candidate Science Questions“ (CSQs), that can be used by ESA and the ACEO to underpin the development of the new strategy. The CSQs are intended to encapsulate a series of pressing Earth system science issues that can be addressed using Earth observation data – either from existing and soon to be launched missions, or from future missions that need to be developed.
A working version of the CSQs is being published in advance of the ESA workshop in order to stimulate discussion, to help identify community priorities, and to guide future work of the study.
Context and Process
The current activity departs from previous ESA EO strategies formulation in two important ways:
- There is consultation with the community early in the process, involving a dedicated study with a science team, and a community workshop
- The approach is determinedly cross-disciplinary, seeking challenges that transcend traditional earth system science domain boundaries
The overall process used for the study is shown below.
In the early stages of the study the project science team split into a number of groups to review and discuss Earth system science priorities from a number of viewpoints. These views are not intended to be a thematic division of science domain but rather a set of perspectives from which to view the earth system science priorities. As such there are some overlaps, and some of the views are orthogonal – our intention is to consider a wide range of viewpoints and tease out cross-disciplinary issues. The list of 12 viewpoints used to initiate the CSQs is shown below:
| Carbon cycle |
Planetary boundaries |
| Water cycle |
Biodiversity and ecosystems |
| Energy cycle |
Coastal zone |
| Solid Earth, including mass changes/large scale hydrology and geomagnetism |
Earthquakes/vulcanism and deformations, mineralogy |
| Climate tipping points |
Polar science |
| Extreme events |
Non topic-specific issues |
At this stage we have identified a series of CSQs which are being used to support community consultation at the ESA Science Strategy workshop. After the workshop, a process of refinement and consolidation will be undertaken. At present we have 57 CSQs and it is expected to reduce this number significantly to help focus the future strategy. Subsequently the objectives for each CSQ will be refined and further details of the geophysical observables and measurement specifications added. Interactions with ACEO will occur at key stages in the process to ensure the utility of the final outputs for ACEO and ESA’s subsequent production of the EO Science Strategy.
Format of the CSQs
- Each of the CSQs are expressed as a summary table, with a supporting narrative. The summary table includes the following elements:
- A high-level summary of the question
- A set of “Knowledge Advancement Objectives”: Specific objectives, for example for process understanding or reducing uncertainties, through which progress towards resolving the question could be measured
- Geophysical Observables: Identification of the main geophysical variables needed to advance the science, noting that there will often be several other supporting datasets needed
- Measurement Specifications: Initial view of the science requirements for datasets providing the geophysical observables. Note as above that many CSQs will need other subsidiary datasets.
- Tools and Models: Beyond EO derived observations, what else is needed. These could be new retrieval algorithms, new data-model assimilation techniques, calibration/validation facilities etc..
- Policies & Benefits: A brief link to the key societal benefit and policy areas that the CSQ’s service. This aspect will be elaborated on in more detail later in the study.
An index is provided that lists the CSQs, and each CSQ is contained in a separate PDF file, which is named with the CSQ number and the first few words of the question.
Some comments on the nature of the CSQs
The CSQs cover a wide range of disciplines and question types. There are varying levels of specificity and maturity. Some questions lend themselves quite well to specification in the format of the table – others are much more difficult, especially in the higher level cross cutting views like Tipping Points and Extreme Events. There are also ranges in the level of specificity. Some are “big” science questions, others more focused on specific topics. In addition to discussion of individual CSQs the workshop should also help the study team and ESA gauge within this range what kind of questions are most helpful in defining future strategy.
