Abstract
The mean seasonal cycle of Antarctic sea-ice extent is asymmetric, with the period of ice retreat being approximately two months shorter than the period of ice advance. This feature is largely consistent in observations from year to year and across different satellite products. The asymmetry is also broadly reproduced by comprehensive climate models across generations from CMIP3 to CMIP6, with limited impacts from internal variability. Using a range of idealized climate models of varying complexity, we show that the seasonal cycle in top-of-atmosphere incident solar radiation drives the asymmetry. Because insolation in southern high latitudes departs from a sinusoid by having a narrow peak of intense brightness in summer and a long period of low light in winter, there is rapid summer ice retreat and gradual winter ice advance. This simple physical explanation is markedly different from those proposed in previous studies.
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Data availability
Data for the processed observations, comprehensive climate model output and idealized model results is available at https://doi.org/10.5281/zenodo.5913959.
Code availability
Code for the idealized climate model is available at https://doi.org/10.5281/zenodo.5913959 and https://eisenman-group.github.io.
References
Pellichero, V., Sallée, J.-B., Chapman, C. C. & Downes, S. M. The Southern Ocean meridional overturning in the sea-ice sector is driven by freshwater fluxes. Nat. Commun. 9, 1789 (2018).
Orsi, A. H., Johnson, G. C. & Bullister, J. L. Circulation, mixing, and production of Antarctic Bottom Water. Prog. Oceanogr. 43, 55–109 (1999).
Massom, R. A. et al. Antarctic ice shelf disintegration triggered by sea ice loss and ocean swell. Nature 558, 383–389 (2018).
Arrigo, K. R., Worthen, D. L., Lizotte, M. P., Dixon, P. & Dieckmann, G. Primary production in Antarctic sea ice. Science 276, 394–397 (1997).
Eayrs, C. et al. Understanding the seasonal cycle of Antarctic sea ice extent in the context of longer-term variability. Rev. Geophys. 57, 1037–1064 (2019).
Gordon, A. L. Seasonality of Southern Ocean sea ice. J. Geophys. Res. 86, 4193–4197 (1981).
Peixoto, J. P. & Oort, A. H. Physics of Climate (American Institute of Physics, 1992).
Enomoto, H. & Ohmura, A. The influences of atmospheric half-yearly cycle on the sea ice extent in the Antarctic. J. Geophys. Res. 95, 9497–9511 (1990).
Stammerjohn, S. E., Drinkwater, M. R., Smith, R. C. & Liu, X. Ice–atmosphere interactions during sea-ice advance and retreat in the western Antarctic Peninsula region. J. Geophys. Res. Oceans 108, 3329 (2003).
Cerrone, D., Fusco, G., Simmonds, I., Aulicino, G. & Budillon, G. Dominant covarying climate signals in the Southern Ocean and Antarctic sea ice influence during the last three decades. J. Clim. 30, 3055–3072 (2017).
Eayrs, C., Faller, D. & Holland, D. M. Mechanisms driving the asymmetric seasonal cycle of Antarctic sea ice in the CESM Large Ensemble. Ann. Glaciol. 61, 171–180 (2020).
Raphael, M. N., Handcock, M. S., Holland, M. M. & Landrum, L. L. An assessment of the temporal variability in the annual cycle of daily Antarctic sea ice in the NCAR Community Earth System Model, Version 2: a comparison of the historical runs with observations. J. Geophys. Res. Oceans 125, e2020JC016459 (2020).
Turner, J. et al. An initial assessment of Antarctic sea ice extent in the CMIP5 models. J. Clim. 26, 1473–1484 (2013).
Zunz, V., Goosse, H. & Massonnet, F. How does internal variability influence the ability of CMIP5 models to reproduce the recent trend in Southern Ocean sea ice extent? Cryosphere 7, 451–468 (2013).
Shu, Q., Song, Z. & Qiao, F. Assessment of sea ice simulations in the CMIP5 models. Cryosphere 9, 399–409 (2015).
Roach, L. A., Dean, S. M. & Renwick, J. A. Consistent biases in Antarctic sea ice concentration simulated by climate models. Cryosphere 12, 365–383 (2018).
Roach, L. A. et al. Antarctic sea ice area in CMIP6. Geophys. Res. Lett. 47, e2019GL086729 (2020).
Shu, Q. et al. Assessment of sea ice extent in CMIP6 with comparison to observations and CMIP5. Geophys. Res. Lett. 47, GL087965 (2020).
Wagner, T. J. W. & Eisenman, I. How climate model complexity influences sea ice stability. J. Clim. 28, 3998–4014 (2015).
Reynolds, R. W., Rayner, N. A., Smith, T. M., Stokes, D. C. & Wang, W. An improved in situ and satellite SST analysis for climate. J. Clim. 15, 1609–1625 (2002).
Meier, W., Fetterer, F., Windnagel, A. & Stewart, J. NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration Version 4 (NSIDC, 2021).
Eisenman, I., Schneider, T., Battisti, D. S. & Bitz, C. M. Consistent changes in the sea ice seasonal cycle in response to global warming. J. Clim. 24, 5325–5335 (2011).
North, G. R. & Coakley, J. A. Differences between seasonal and mean annual energy-balance model calculations of climate and climate sensitivity. J. Atmos. Sci. 36, 1189–1204 (1979).
Donohoe, A., Dawson, E., McMurdie, L., Battisti, D. S. & Rhines, A. Seasonal asymmetries in the lag between insolation and surface temperature. J. Clim. 33, 3921–3945 (2020).
Blanchard-Wrigglesworth, E., Donohoe, A., Roach, L. A., DuVivier, A. & Bitz, C. M. High-frequency sea ice variability in observations and models. Geophys. Res. Lett. 48, e2020GL092356 (2021).
Kay, J. E. et al. The Community Earth System Model (CESM) Large Ensemble project: a community resource for studying climate change in the presence of internal climate variability. Bull. Am. Meteorol. Soc. 96, 1333–1349 (2015).
SIMIP Community Arctic sea ice in CMIP6. Geophys. Res. Lett. 47, e2019GL086749 (2020).
Notz, D. et al. The CMIP6 Sea-Ice Model Intercomparison Project (SIMIP): understanding sea ice through climate-model simulations. Geosci. Model Dev. 9, 3427–3446 (2016).
Huybers, P. & Eisenman, I. Integrated Summer Insolation Calculations IGBP PAGES/WDCA Contribution Series 2006-079 (NOAA/NCDC Paleoclimatology Program, 2006).
Acknowledgements
We thank C. Eayrs for helpful discussions. This work was supported by the Scientific Committee on Antarctic Research (SCAR) Fellowship Program; the National Oceanic and Atmospheric Administration (NOAA) Climate and Global Change Postdoctoral Fellowship Program, which is administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award NA18NWS4620043B; US National Science Foundation grants OPP-1643445, OCE-2048590 and OPP-1643431; and NOAA grant NA18OAR4310274.
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T.J.W.W. and L.A.R. conceived the study question. I.E., L.A.R. and T.J.W.W. designed the research, constructed the idealized models, interpreted the results and developed the conclusions. L.A.R. analysed the observations and CMIP output. C.M.B. and E.B.-W. assisted with initial attempts to address the question. L.A.R., I.E. and T.J.W.W. wrote the manuscript with contributions from all co-authors.
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Nature Geoscience thanks Clare Eayrs, Kenneth Golden and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Tom Richardson, in collaboration with the Nature Geoscience team.
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Roach, L.A., Eisenman, I., Wagner, T.J.W. et al. Asymmetry in the seasonal cycle of Antarctic sea ice driven by insolation. Nat. Geosci. 15, 277–281 (2022). https://doi.org/10.1038/s41561-022-00913-6
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DOI: https://doi.org/10.1038/s41561-022-00913-6
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