Interannual SAM modulation of Antarctic sea ice extent does not account for its long-term trends: implications for the role of ozone depletion

Polvani, L. M., Banerjee, A., Chemke, R., Doddridge, E. W., Ferreira, D. ORCID: https://orcid.org/0000-0003-3243-9774, Gnanadesikan, A., Holland, M. A., Kostov, Y., Marshall, J., Seviour, W. J. M., Solomon, S. and Waugh, D. W. (2021) Interannual SAM modulation of Antarctic sea ice extent does not account for its long-term trends: implications for the role of ozone depletion. Geophysical Research Letters, 48 (21). ISSN 0094-8276 doi: 10.1029/2021GL094871

Abstract/Summary

The expansion of Antarctic sea ice since 1979 in the presence of increasing greenhouse gases remains one of the most puzzling features of current climate change. Some studies have proposed that the formation of the ozone hole, via the Southern Annular Mode, might explain that expansion, and a recent study highlighted a robust causal link between summertime Southern Annular Mode (SAM) anomalies and sea ice anomalies in the subsequent autumn. Here we show that many models are able to capture this relationship between the SAM and sea ice, but also emphasize that the SAM only explains a small fraction of the year-to-year variability. Finally, examining multidecadal trends, in models and observations, we confirm the findings of several previous studies and conclude that the SAM – and thus the ozone hole – are not the primary drivers of the sea ice expansion around Antarctica in recent decades.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/100716
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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