Critical processes such as sea-ice production, water mass transformation, energy and gas exchange, ice-shelf basal melt and cloud formation are strongly influenced by atmosphere-ice ocean interactions occurring regionally around coastal Antarctica. Regions where these interactions are particularly strong are characterised by polynya formation, strong winds, large ocean-atmosphere temperature differences and strong turbulent fluxes of heat, momentum, moisture and greenhouse gases. These ‘hotspot’ regions play an outsized role in setting the mean state and variability of ocean circulation (regional and global) and sea ice formation.
A major problem is that accurate representation in models of the critical processes in these regions and their impacts is challenging. This is compounded by spatially and temporally sparse atmospheric and oceanic observations. Satellite-based estimates of winds are strongly limited by the presence of sea ice (and icebergs) and restricted to the surface, and satellite-based estimates of turbulent fluxes are not possible yet. Without high quality observations to help develop models, there remains large uncertainty in the representation of surface fluxes and the associated processes and interactions.
Past observational and modelling studies have generally been limited geographically to specific sectors or polynya systems. However, the science questions relating to, for example water mass transformation and sea-ice production involve multiple regions around Antarctica. Four hotspot supersites are proposed as focal points for effort due to their major role in a range of processes and their importance in the global overturning circulation (Schmidt et al., 2023) (Fig.1). These are the Weddell Sea (primarily the Ronne Polynya), Prydz Bay, the Adelie coast and the Ross Sea. This does not exclude the possibility for specific targeted studies of other locations, particularly in areas where warm Southern Ocean waters can reach ice shelves to drive basal melting and polynyas can modulate this heat delivery (e.g. Amundsen Sea, O’Connor et al., 2025). To make significant advances in model representation of ocean-ice atmosphere interactions in all hotspot regions, coordinated observations and modelling efforts are required. Collaboration across multiple national programmes and institutions would be central to such an approach to enable coordinated observations at different locations.
The main new aspects that this working group would bring are:
This is a highly multi-disciplinary topic, involving modellers and observationalists in the atmosphere, sea ice and ocean realms. It also encompasses both the physical dynamics and chemistry of ocean-ice-atmosphere fluxes. This WG aligns most closely with Theme 1: Southern Ocean and Antarctic heat, freshwater, carbon and other elements cycles and their response to climate change. However, there will be strong cross-disciplinary links to the other themes that will be maintained through having reps from each one as members of this WG. In particular Themes 2, 6 and 7.
The main aim of this proposed working group is to promote and enable an Antarctic-wide approach to observing and modelling hotspots of atmosphere-ice-ocean interaction, with a focus on four key supersites around near-coastal Antarctica. The working group would provide a mechanism for research proposals and projects across different national programmes to link together and help answer questions on Antarctica’s integrated interactions with the wider global climate system that would be much more challenging to address by any project alone.
The specific objectives are
This proposed working group will combine observational and modelling approaches.
The main methods will be:
A coordinated set of agreed standard measurements will be defined for the above platforms, in coordination with protocols developed in relevant InSync themes and the SOOS SOFLUX initiative on air-sea fluxes. There will also be standardisation of data format working with InSync themes and SCAR’s Committee on Data Management. This will help to ensure effective collaboration between component projects to help achieve the overarching Antarctic-wide objectives
The first step will be for this working group to help support and coordinate proposals for funding to observe and model major hotspot locations around Antarctica, which is a task too large for the logistical capabilities of any one country/institution. A white paper will be written to help leverage funding from national programmes.
Key deliverables of the group will be:
For any projects that are funded:
| Timeframe | Task |
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As outlined above the aim of this proposed working group is to provide a supporting community and framework to facilitate and coordinate research proposals and projects on the topic of regional hotspots of ocean-atmosphere interaction around coastal Antarctica. The ultimate objectives will of course depend on securing research funding, but there are key activities and milestones to coordinate research plans. Specifically: |
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| In year one (2026): |
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| In year two (2027): |
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| In year three (2028): |
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| In year four (2029): |
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