Abstract
Here we study the Arctic and Antarctic sea-ice area records provided by the National Snow and Ice Data Center (NSIDC). These records reveal an opposite climatic behavior: since 1978 the Arctic sea-ice area index decreased, that is, the region has warmed, while the Antarctic sea-ice area index increased, that is, the region has cooled. During the last 7 years the Arctic sea-ice area has stabilized while the Antarctic sea-ice area has increased at a rate significantly higher than during the previous decades; that is, the sea-ice area of both regions has experienced a positive acceleration. This result is quite robust because it is confirmed by alternative temperature climate indices of the same regions. We also found that a significant 4-5-year natural oscillation characterizes the climate of these sea-ice polar areas. On the contrary, we found that the CMIP5 general circulation models have predicted significant warming in both polar sea regions and failed to reproduce the strong 4-5-year oscillation. Because the CMIP5 GCM simulations are inconsistent with the observations, we suggest that important natural mechanisms of climate change are missing in the models.
Highlights
We found that the CMIP5 general circulation models have predicted significant warming in both polar sea regions and failed to reproduce the strong 4-5-year oscillation
This paper aims to study in detail the polar sea-ice area index records, compare the observed interannual and decadal patterns among several alternative climatic temperature records of the same regions, and test whether the Coupled Model Intercomparison Project Phase 5 general circulation models (CMIP5 GCMs) [14] predict the observed pattern
The Arctic and the Antarctica are characterized by an opposite climatic behavior in sea-ice area extensions
Summary
The annual smooth record of the Antarctic sea-ice area has increased from about 8.5 ⋅ 106 km in 1978 to about 9.5 ⋅ 106 km in 2014 with a linear rate of 0.020 ± 0.001 km2/year.
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