Arctic sea ice response to atmospheric forcings with varying levels of anthropogenic warming and climate variability
Article first published online: 28 OCT 2010
Copyright 2010 by the American Geophysical Union.
Geophysical Research Letters
Volume 37, Issue 20, October 2010
How to Cite
2010), Arctic sea ice response to atmospheric forcings with varying levels of anthropogenic warming and climate variability, Geophys. Res. Lett., 37, L20505, doi:10.1029/2010GL044988., , and (
- Issue published online: 28 OCT 2010
- Article first published online: 28 OCT 2010
- Manuscript Accepted: 20 SEP 2010
- Manuscript Revised: 8 SEP 2010
- Manuscript Received: 4 AUG 2010
- sea ice;
- climate change
 Numerical experiments are conducted to project arctic sea ice responses to varying levels of future anthropogenic warming and climate variability over 2010–2050. A summer ice-free Arctic Ocean is likely by the mid-2040s if arctic surface air temperature (SAT) increases 4°C by 2050 and climate variability is similar to the past relatively warm two decades. If such a SAT increase is reduced by one-half or if a future Arctic experiences a range of SAT fluctuation similar to the past five decades, a summer ice-free Arctic Ocean would be unlikely before 2050. If SAT increases 4°C by 2050, summer ice volume decreases to very low levels (10–37% of the 1978–2009 summer mean) as early as 2025 and remains low in the following years, while summer ice extent continues to fluctuate annually. Summer ice volume may be more sensitive to warming while summer ice extent more sensitive to climate variability. The rate of annual mean ice volume decrease relaxes approaching 2050. This is because, while increasing SAT increases summer ice melt, a thinner ice cover increases winter ice growth. A thinner ice cover also results in a reduced ice export, which helps to further slow ice volume loss. Because of enhanced winter ice growth, arctic winter ice extent remains nearly stable and therefore appears to be a less sensitive climate indicator.