Publication Date:
2019-09-23
Description:
The Southern Ocean is thought to be one of the most energetic regions in the world’s oceans. As a result, it is a location of vigorous diapycnal mixing of heat, salt and biogeochemical properties1, 2, 3. At the same time, the Southern Ocean is poorly sampled, not least because of its harsh climate and remote location. Yet the spatial and temporal variation of diapycnal diffusivity in this region plays an important part in the large-scale ocean circulation and climate4, 5, 6. Here we use high-resolution hydrographic profiles from Argo floats in combination with the Iridium communications system to investigate diapycnal mixing in the Southern Ocean. We find that the spatial distribution of turbulent diapycnal mixing in the Southern Ocean at depths between 300 and 1,800 m is controlled by the topography, by means of its interaction with the Antarctic Circumpolar Current. The seasonal variation of this mixing can largely be attributed to the seasonal cycle of surface wind stress and is more pronounced in the upper ocean over flat topography. We suggest that additional high-resolution profiles from Argo floats will serve to advance our understanding of mixing processes in the global ocean interior.
Type:
Article
,
PeerReviewed
Format:
text
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