After the discussions during the thematic workshop "Interaction at the Air-Sea - Cryosphere interface in the Southern Ocean / Observation, modelling and impact analysis", which was held during the 12th Scientific Days of the French National Committee for Arctic and Antarctic Research (CNFRA) from May 25 to 27 in Villeurbanne (Université Claude Bernard Lyon 1), a forward-looking memo was drafted with input from the numerous scientists at the meeting, representing almost all of the major research sectors. No less than 45 communications were also presented to a hundred participants. These high-level discussions were attended by Yvan Griboval, our President, and a new member of CNFRA, as an enthusiastic and attentive spectator. Here is an excerpt from the forward-looking memo.

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"The southern climate system has changed rapidly in recent decades: regional warming of the atmosphere; reorganization of the winds associated with an intensification of the "Southern Annular" climate mode; spatial reorganization of the sea ice; acidification, warming and desalination of the ocean; reduction in the krill population; melting of certain floating glaciers; acceleration in the outflow of major glaciers in West Antarctica and the Peninsula.

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These changes in the southern climate system have a global impact. For example, ocean changes may affect the future ability of the Southern Ocean to absorb heat and carbon from the atmosphere and, ultimately, its ability to buffer climate change. At present the Southern Ocean absorbs about 50% of anthropogenic ocean carbon and more than 75% of anthropogenic ocean heat. The change in the mass balance of the Antarctic continent has a major impact on future sea level rise. This is one of the main uncertainties in the predictions of the societal impact of climate change associated with rising sea levels. It is suspected that such changes have occurred in the past in response to natural paleo-climate forcers, causing major imbalances in the Earth's climate. We urgently need to understand the current trends, forced today by anthropogenic phenomena, in the light of paleo-climate events.

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Atmospheric, oceanic and cryospheric changes are intrinsically coupled / interrelated and must be jointly addressed. This represents a major challenge for research in Antarctica since the study area to be treated in order to address the entire system covers a wide range of latitudes, from subtropical regions to the South Pole. In this sense, France has a major and unique asset with which to study the southern climate system, thanks to a long-standing distribution of national bases enabling virtually continuous climate monitoring from North to South in East Antarctica, from the Island of New Amsterdam at 37ºS, to the Dome C base, at 75ºS. This distribution of bases makes it potentially possible to monitor the climate system as various oceanic fronts pass by to the coast of Antarctica, and then the entire continent (coast, plateau and the transition between these two areas).

 

We believe that this unique potential for French research must be recognized and promoted at all costs. To advance the understanding of the southern climate system and its global impact, it is urgent to support interdisciplinary integration projects. The projects should involve all of the environmental factors (ocean, ice, and atmosphere) because the system can only be understood if it is studied in its entirety. The analysis of the processes and recent changes need to be put into perspective in relation to previous paleoclimatology data.

 

East Antarctica (45°W - 168°E) is an extremely interesting natural laboratory for such an integrated analysis of the southern climate system. The region and the surrounding oceans offer a wide range of dynamic systems, regions with extremes in terms of the intensity of the oceanic and atmospheric currents and turbulence, associated with a high level of biological activity (Crozet, Kerguelen). The air-sea-ice interactions are intense in this key region for the formation of bottom water and for ecosystems (marginal ice zone, Adélie Land, Mertz Glacier).

 

Finally, although supposedly stable, the ice cap of East Antarctica represents a potential contribution to the global mean sea level rise much higher than the rest of the continent. France's unique access to this vast natural southern laboratory will allow us to address a series of pressing issues...

 

In this context, the existence of perennial human resources enabling observations including in winter should be supported. This being said, there is a large community in France, active in the high southern latitudes, with an internationally recognized wide range of approaches. We wish times and places for discussion to be favoured in this community, in order to foster the emergence of and support for ambitious research projects."

 

 

To access the full report on the 12th Scientific Days of the French National Committee for Arctic and Antarctic Research (CNFRA)