Antarctica InSync Cross-Cutting Theme Earth Observation: Unleashing the potential of Earth Observation to improve monitoring and understanding of Antarctica and the Southern Ocean [white paper]

Advances in satellite Earth Observation (EO) have enabled comprehensive and continuous monitoring, and characterisation, of Antarctica and the Southern Ocean. EO data products provide essential information to tackle the scientific priorities of Antarctica InSync, including crucial spatial and temporal context for in-situ campaigns and modelling. The wealth of EO data products enables scientific research priorities to be addressed, such as understanding impacts of climate change and variability across ice sheets, ice shelves, sea ice, ocean, atmosphere and ecosystems, investigating trends, extremes and feedbacks.

However, there remain many areas for improvement. In the context of Antarctica InSync the EO scientific community have identified the following priorities:

- It is vital to continue to improve satellite EO pf Antarctica and the Southern Ocean. Efforts should target:
o Extending the observational record,
o Increasing the range of measured variables,
o improving spatial and temporal resolution,
o quantifying and reducing measurement uncertainties,
o increasing data accessibility,
o creating new satellite EO capabilities.

- Integrated EO and campaign data should from the core observational baseline for InSync.

- Antarctica InSync provides a valuable opportunity to advance science through EO-led science investigations and collaboration with:
- In-situ, ship-based and airborne campaigns:
o In-situ observations are a critical resource for validation and calibration of EO data. Coordination with fieldwork teams is vital to ensure all possible opportunities for EO cal/val
are maximised. Ideally, in-situ observations should be maintained for longer periods (i.e. years) to enable ongoing cal/val activities through multiple seasons.
o EO data provides valuable information on where to target in-situ activities, such as significant areas of change and regions where key physical processes are exemplified. These regions should be coordinated across Antarctic InSync science themes as supersites.

- Modelling community:
o EO data provides crucial information for model initialization, assimilation and validation.
o Improved process understanding, driven by analysis of EO data, leads to improved representation of complex processes in models and more accurate future projections

- International, national and commercial EO capability:
o There is strong interest within the EO community for improved coordination between space agencies and substantial scientific potential in high-resolution commercial data products. Access to these data could be achieved through strengthened collaboration with commercial providers.