There is a new paper on the climate of the higher latitudes. It is
Chylek, P., C. K. Folland, G. Lesins, and M. K. Dubey (2010), Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures, Geophys. Res. Lett., 37, L08703, doi:10.1029/2010GL042793.
The abstract reads
“Understanding the phase relationship between climate changes in the Arctic and Antarctic regions is essential for our understanding of the dynamics of the Earth’s climate system. In this paper we show that the 20th century detrended Arctic and Antarctic temperatures vary in anti‐phase seesaw pattern – when the Arctic warms the Antarctica cools and visa versa. This is the first time that a bi‐polar seesaw pattern has been identified in the 20th century Arctic and Antarctic temperature records. The Arctic (Antarctic) detrended temperatures are highly correlated (anti‐correlated) with the Atlantic Multi‐decadal Oscillation (AMO) index suggesting the Atlantic Ocean as a possible link between the climate variability of the Arctic and Antarctic regions. Recent accelerated warming of the Arctic results from a positive reinforcement of the linear warming trend (due to an increasing concentration of greenhouse gases and other possible forcings) by the warming phase of the multidecadal climate variability (due to fluctuations of the Atlantic Ocean circulation).”
The summary in the paper reads in part
A bi‐polar seesaw pattern of the paleo temperature has been observed earlier in the Greenland and Antarctic ice core data. For the first time we identify a bi‐polar seesaw pattern in the 20th century Arctic and Antarctic instrumental temperature records. The detrended multidecadal scale variability of the Arctic and Antarctic temperature time series are highly anticorrelated. When the Arctic warms Antarctica cools and vice versa. This multidecadal variability combines with the general warming trend (presumably dominated by anthropogenic GHGs) to produce the observed Arctic and Antarctic temperature patterns. The intense Arctic warming since the 1970s (Figure 1a) arises from an additive combination of the general global warming trend with the warming phase of the multidecadal climate oscillation, while in Antarctica the cooling phase of the multidecadal oscillation opposes the general warming trend leading to essentially no significant Antarctic temperature change since the 1970s…”
This is another new paper that documents why we need a regionally focused assessment of atmospheric and ocean circulation changes with respect to climate variability and change rather than using a global average surface temperature as primary climate change metric. My only disagreement with the paper is that in indicates there is an overarching “general warming trend” when, as we discussed last week (e.g. see, see and see), climate system heat changes are clearly nonlinear as warming has essentially ceased since at least 2005 through mid-2009 (the last time we have seen the data). Moreover, as discussed by Roy Spencer (e.g. see) and in our 2009 EOS article (see), it is inaccuate to just focus on the greenhouse gases with respect to how the climate system is being altered.