Auger M., Morrow R., Kestenare Elodie, Sallee J. B., Cowley R. (2021). Southern Ocean in-situ temperature trends over 25 years emerge from interannual variability. Nature Communications, 12 (1), p. 514 [9 p.]. ISSN 2041-1723.
Titre du document
Southern Ocean in-situ temperature trends over 25 years emerge from interannual variability
Année de publication
Auger M., Morrow R., Kestenare Elodie, Sallee J. B., Cowley R.
Nature Communications, 2021,
12 (1), p. 514 [9 p.] ISSN 2041-1723
Despite playing a major role in global ocean heat storage, the Southern Ocean remains the most sparsely measured region of the global ocean. Here, a unique 25-year temperature time-series of the upper 800m, repeated several times a year across the Southern Ocean, allows us to document the long-term change within water-masses and how it compares to the interannual variability. Three regions stand out as having strong trends that dominate over interannual variability: warming of the subantarctic waters (0.290.09 degrees C per decade); cooling of the near-surface subpolar waters (-0.07 +/- 0.04 degrees C per decade); and warming of the subsurface subpolar deep waters (0.04 +/- 0.01 degrees C per decade). Although this subsurface warming of subpolar deep waters is small, it is the most robust long-term trend of our section, being in a region with weak interannual variability. This robust warming is associated with a large shoaling of the maximum temperature core in the subpolar deep water (39 +/- 09m per decade), which has been significantly underestimated by a factor of 3 to 10 in past studies. We find temperature changes of comparable magnitude to those reported in Amundsen-Bellingshausen Seas, which calls for a reconsideration of current ocean changes with important consequences for our understanding of future Antarctic ice-sheet mass loss. The Southern Ocean takes up the most heat and carbon, yet because of its remote and harsh location, it remains relatively sparsely measured. Here the authors use a 25 year temperature series which shows a clear, long term trend in subsurface warming that emerges from interannual variability.
Plan de classement
Limnologie physique / Océanographie physique 
Fonds IRD [F B010080903]