The central role of diminishing sea ice in recent Arctic temperature amplification

Journal name:
Nature
Volume:
464,
Pages:
1334–1337
Date published:
DOI:
doi:10.1038/nature09051
Received
Accepted

The rise in Arctic near-surface air temperatures has been almost twice as large as the global average in recent decades1, 2, 3—a feature known as ‘Arctic amplification’. Increased concentrations of atmospheric greenhouse gases have driven Arctic and global average warming1, 4; however, the underlying causes of Arctic amplification remain uncertain. The roles of reductions in snow and sea ice cover5, 6, 7 and changes in atmospheric and oceanic circulation8, 9, 10, cloud cover and water vapour11, 12 are still matters of debate. A better understanding of the processes responsible for the recent amplified warming is essential for assessing the likelihood, and impacts, of future rapid Arctic warming and sea ice loss13, 14. Here we show that the Arctic warming is strongest at the surface during most of the year and is primarily consistent with reductions in sea ice cover. Changes in cloud cover, in contrast, have not contributed strongly to recent warming. Increases in atmospheric water vapour content, partly in response to reduced sea ice cover, may have enhanced warming in the lower part of the atmosphere during summer and early autumn. We conclude that diminishing sea ice has had a leading role in recent Arctic temperature amplification. The findings reinforce suggestions that strong positive ice–temperature feedbacks have emerged in the Arctic15, increasing the chances of further rapid warming and sea ice loss, and will probably affect polar ecosystems, ice-sheet mass balance and human activities in the Arctic2.

At a glance

Figures

  1. Surface amplification of temperature trends, 1989-2008.
    Figure 1: Surface amplification of temperature trends, 1989–2008.

    Temperature trends averaged around circles of latitude for winter (December–February; a), spring (March–May; b), summer (June–August; c) and autumn (September–November; d). The black contours indicate where trends differ significantly from zero at the 99% (solid lines) and 95% (dotted lines) confidence levels. The line graphs show trends (same units as in colour plots) averaged over the lower part of the atmosphere (950–1,000hPa; solid lines) and over the entire atmospheric column (300–1,000hPa; dotted lines). Red shading indicates that the lower atmosphere has warmed faster than the atmospheric column as whole. Blue shading indicates that the lower atmosphere has warmed slower than the atmospheric column as a whole.

  2. Temperature trends linked to changes in sea ice.
    Figure 2: Temperature trends linked to changes in sea ice.

    Temperature trends over the 1989–2008 period averaged around circles of latitude for winter (a), spring (b), summer (c) and autumn (d). The trends are derived from projections of the temperature field on the sea ice time series (Methods Summary). The black contours indicate where the ice–temperature regressions differ significantly from zero at the 99% (solid lines) and 95% (dotted lines) uncertainty levels.

  3. Impacts of cloud-cover changes on the net surface radiation.
    Figure 3: Impacts of cloud-cover changes on the net surface radiation.

    Mean net surface radiation (short-wave plus long-wave) over the 1989–2008 period under cloudy-sky (solid lines) and clear-sky (dotted lines) conditions. Means are averaged around circles of latitude for winter (a), spring (b), summer (c) and autumn (d). The fluxes are defined as positive in the downward direction. Red shading indicates that the presence of cloud has a net warming effect at the surface. Blue shading indicates that the presence of cloud has a net cooling effect at the surface. The dashed lines show the approximate edge of the Arctic basin. Symbols show latitudes where increases (triangles) and decreases (crosses) in total cloud cover significant at the 99% uncertainty level are found.

  4. Atmospheric moisture trends, 1989-2008.
    Figure 4: Atmospheric moisture trends, 1989–2008.

    Specific humidity trends averaged around circles of latitude for June–October: total trends (a); trends that are linked to changes in sea ice (b). The black contours indicate where trends (a) or humidity–ice regressions (b) differ significantly from zero at the 99% (solid lines) and 95% (dotted lines) uncertainty levels. In a, triangles show latitudes where increases in the surface latent-heat flux significant at the 99% uncertainty level are found.

References

  1. Solomon, S. et al., eds. Climate Change 2007: The Physical Science Basis (Cambridge Univ. Press, 2007)
  2. Symon, C., Arris, L., Heal, B. eds. Arctic Climate Impact Assessment (Cambridge Univ. Press, 2004)
  3. Serreze, M. C. & Francis, J. A. The Arctic amplification debate. Clim. Change 76, 241264 (2006)
  4. Gillett, N. P. et al. Attribution of polar warming to human influence. Nature Geosci. 1, 750754 (2008)
  5. Stroeve, J., Holland, M. M., Meir, W., Scambos, T. & Serreze, M. Arctic sea ice decline: faster than forecast. Geophys. Res. Lett. 34 doi:10.1029/2007GL029703 (2007)
  6. Serreze, M. C., Holland, M. M. & Stroeve, J. Perspectives of the Arctic’s shrinking ice cover. Science 315, 15331536 (2007)
  7. Comiso, J. C., Parkinson, C. L., Gersten, R. & Stock, L. Accelerated decline in the Arctic sea ice cover. Geophys. Res. Lett. 35 doi:10.1029/2007GL031972 (2008)
  8. Graversen, R. G., Mauritsen, T., Tjernström, M., Källén, E. & Svensson, G. Vertical structure of recent Arctic warming. Nature 451, 5356 (2008)
  9. Simmonds, I. & Keay, K. Extraordinary September Arctic sea ice reductions and their relationships with storm behavior over 1979–2008. Geophys. Res. Lett. 36 doi:10.1029/2009GL039810 (2009)
  10. Chylek, P., Folland, C. K., Lesins, G., Dubey, M. K. & Wang, M. Arctic air temperature change amplification and the Atlantic multidecadal oscillation. Geophys. Res. Lett. 36 doi:10.1029/2009GL038777 (2009)
  11. Schweiger, A. J., Lindsay, R. W., Vavrus, S. & Francis, J. A. Relationships between Arctic sea ice and clouds during autumn. J. Clim. 21, 47994810 (2008)
  12. Francis, J. A. & Hunter, E. Changes in the fabric of the Arctic’s greenhouse blanket. Environ. Res. Lett. 2 doi:10.1088/1748–9326/2/4/045011 (2007)
  13. Holland, M. M., Bitz, C. M. & Tremblay, B. Future abrupt reductions in the summer Arctic sea ice. Geophys. Res. Lett. 33 doi:10.1029/2006GL028024 (2006)
  14. Boé, J., Hall, A. & Qu, X. September sea ice cover in the Arctic Ocean projected to vanish by 2100. Nature Geosci. 2, 341343 (2009)
  15. Serreze, M. C., Barrett, A. P., Stroeve, J. C., Kindig, D. N. & Holland, M. M. The emergence of surface-based Arctic amplification. Cryosphere 3, 1119 (2009)
  16. Holland, M. M. & Bitz, C. M. Polar amplification of climate change in coupled models. Clim. Dyn. 21, 221232 (2003)
  17. Winton, M. Amplified climate change: what does surface albedo feedback have to do with it? Geophys. Res. Lett. 33 doi:10.1029/2005GL025244 (2006)
  18. Lu, J. & Cai, M. Seasonality of polar surface warming amplification in climate simulations. Geophys. Res. Lett. 36 doi:10.1029/2009GL040133 (2009)
  19. Graversen, R. G. & Wang, M. Polar amplification in a coupled model with locked albedo. Clim. Dyn. 33, 629643 (2009)
  20. Boé, J., Hall, A. & Qu, X. Current GCMs’ unrealistic negative feedback in the Arctic. J. Clim. 22, 46824695 (2009)
  21. Smedsrud, L. H., Sorteberg, A. & Kloster, K. Recent and future changes of the Arctic sea-ice cover. Geophys. Res. Lett. 35 doi:10.1029/2008GL034813 (2008)
  22. Deser, C., Tomas, R., Alexander, M. & Lawrence, D. The seasonal atmospheric response to projected Arctic sea ice loss in the late twenty-first century. J. Clim. 23, 333351 (2010)
  23. Thorne, P. W. Arctic tropospheric warming amplification? Nature 455, E1E2 (2008)
  24. Grant, A. N., Brönnimann, S. & Haimberger, L. Recent Arctic warming vertical structure contested. Nature 455, E2E3 (2008)
  25. Bitz, C. M. & Fu, Q. Arctic warming aloft is data set dependent. Nature 455, E3E4 (2008)
  26. Dee, D. P. & Uppala, S. Variational bias correction of satellite radiance data in the ERA-Interim reanalysis. Q. J. R. Meteorol. Soc. 135, 18301841 (2009)
  27. Higgins, M. E. & Cassano, J. J. Impacts of reduced sea ice on winter Arctic atmospheric circulation, precipitation and temperature. J. Geophys. Res. 114 doi:10.1029/2009JD011884 (2009)
  28. Kwok, R. & Rothrock, D. A. Decline in Arctic sea ice thickness from submarine and ICESat records: 1958–2008. Geophys. Res. Lett. 36 doi:10.1029/2009GL039035 (2009)
  29. Lindsay, R. W., Zhang, J., Schweiger, A., Steele, M. & Stern, H. Arctic sea ice retreat in 2007 follows thinning trend. J. Clim. 22, 165176 (2009)
  30. Intrieri, J. M. et al. An annual cycle of Arctic surface cloud forcing at SHEBA. J. Geophys. Res. 107 doi:10.1029/2000JC000439 (2002)

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Author information

Affiliations

  1. School of Earth Sciences, University of Melbourne, Melbourne, Victoria 3010, Australia

    • James A. Screen &
    • Ian Simmonds

Contributions

The analysis was performed and the manuscript written by J.A.S. Both authors contributed with ideas and discussions.

Competing financial interests

The authors declare no competing financial interests.

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Supplementary information

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  1. Supplementary Information (249K)

    This file contains a Supplementary Discussion, Supplementary Figures 1-2 with legends, Supplementary Table 1 and References.

Comments

  1. Report this comment #15449

    Arno Arrak said:

    This paper has only limited value, if any, for understanding arctic warming. The warming started suddenly over a hundred years ago as Kaufman et al. have shown but they barely go back a few decades. As to the arctic "amplification," Polyakov has looked for it and could not find any. The warming started suddenly at the end of a two thousand year cooling period that Kaufman et al. correctly attribute to earth orbital variations. But a sudden beginning requires an equally sudden cause and the greenhouse effect cannot do that. This is because the absorptivity of carbon dioxide in the infrared is a physical property of that gas and cannot be changed. If you want more absorption so as to create a warming you must put more gas into the atmosphere and we know this did not happen. This leaves ocean currents as the only possible source of delivering warmth to the Arctic. This hypothesis requires that a rearrangement of the North Atlantic current system at the turn of the twentieth century and not some greenhouse effect is the true cause of arctic warming. Reduced sea ice cover has nothing to do with causing it but is a consequence of warming.

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