Role of Polar Amplification in Long-Term Surface Air Temperature Variations and Modern Arctic Warming

Abstract

This study uses an extensive dataset of monthly surface air temperature (SAT) records (including previously unutilized) from high-latitude (>60°N) meteorological land stations. Most records have been updated by very recent observations (up to December 2008). Using these data, a high-latitude warming rate of 1.36°C century−1 is documented for 1875–2008—the trend is almost 2 times stronger than the Northern Hemisphere trend (0.79°C century−1), with an accelerated warming rate in the most recent decade (1.35°C decade−1). Stronger warming in high-latitude regions is a manifestation of polar amplification (PA). Changes in SAT suggest two spatial scales of PA—hemispheric and local. A new stable statistical measure of PA linking high-latitude and hemispheric temperature anomalies via a regression relationship is proposed. For 1875–2008, this measure yields PA of ∼1.62. Local PA related to the ice–albedo feedback mechanisms is autumnal and coastal, extending several hundred kilometers inland. Heat budget estimates suggest that a recent reduction of arctic ice and anomalously high SATs cannot be explained by ice–albedo feedback mechanisms alone, and the role of large-scale mechanisms of PA of global warming should not be overlooked.

A baseline for the vertical distribution of the stable carbon isotopes of dissolved inorganic carbon (δ13CDIC) in the Arctic Ocean

“…2b). In the Canada Basin, d 13 C DIC values range between -0.6 and 2 % in the upper 200-250 m with strong regional differences (Fig. 2b).…”

“…Stable carbon isotopes of dissolved inorganic carbon (d 13 C DIC ) in the Arctic Ocean are likely to change in the near future with rapidly changing climate conditions. Climate reconstructions of the recent geological past characterize our climate system under different preconditions and aid to better evaluate the modern climate change and its future projections.…”

“…While the factors controlling oxygen isotopes (d 18 O) in carbonate shells in the Arctic are reasonably well understood (e.g., [51]), this is not the case for stable carbon isotopes (d 13 C). Furthermore, we have only a rudimentary understanding of the complex interplay of biological and physical-chemical factors influencing the d 13 C DIC that is recorded in the d 13 C of carbonate shells (e.g., [27,43]). With the ongoing climate change and the accompanying changes in Arctic hydrography as well as biological productivity and communities, it is important to assess and further understand the modern distribution of d 13 C DIC in the Arctic Ocean.…”

“…This situation indicates that the Arctic environment is especially sensitive to climate change and that significant further changes may occur in this part of the Earth in the near future as feedback reactions (e.g., [13,24]). Under present conditions, Arctic sea ice is mainly produced over the broad continental shelves that cover nearly half of the Arctic Ocean area and, to a large extent, are seasonally free of sea ice (e.g., [29]).…”

Mechanisms influencing seasonal to inter-annual prediction skill of sea ice extent in the Arctic Ocean in MIROC

“…The Arctic has warmed more than twice as much as the global average (e.g., Bekryaev et al, 2010;Cohen et al, 2014), this is referred to as Arctic amplification. Sea ice reduction resulting from climate change is one of the main processes contributing to Arctic amplification (e.g., Pithan and Mauritsen, 2014).…”