An Arctic and antarctic perspective on recent climate change

Abstract

Abstract:We contrast recent climatic and environmental changes and their causes in the Arctic and the Antarctic. There are continuing increases in surface temperatures, losses of sea ice and tundra, and warming of permafrost over broad areas of the Arctic, while most of the major increase in Antarctic temperatures is on the Antarctic Peninsula associated with sea ice loss in the Bellingshausen-Amundsen Seas sector. While both natural atmospheric and oceanic variability, and changes in external forcing including increased greenhouse gas concentrations, must be considered in the quest for understanding such changes, the interactions and feedbacks between system components are particularly strong at high latitudes. For the 1950s to date in the Arctic and for 1957 to date in the Antarctic, positive trends in large-scale atmospheric circulation represented by the Arctic oscillation (AO) and Antarctic oscillations (AAO) and the Pacific North American (PNA) pattern contribute to the long-term temperature trends. However, continuing Arctic trends during the last decade of near neutral AO will require alternate explanations. The trend in the AAO since 1950 is larger than expected from natural variability and may be associated with the decrease in stratospheric ozone over Antarctic. The persistence shown in many Arctic and Antarctic Peninsula components of climate and their influence through possible feedback supports continuation of current trends over the next decade. One can expect large spatial and temporal differences, however, from the relative contributions of intrinsic variability, external forcing, and internal feedback/amplifications. It is particularly important to resolve regional feedback processes in future projections based on modeling scenarios.

Observations: Cryosphere

“…The ice area study across East Antarctica (10°W to 172°E) revealed a statistically significant increase of 1.43 ± 0.3% per year, this trend agreeing with other shortterm regional trends in overall sea ice (pack ice + fast ice) for different sectors of the coast Comiso, 2009). Pezza et al (2012) also report a modest increasing trend in sea-ice area around Antarctica over the era of satellite coverage, as documented by , , , Turner et al (2007), and . Pezza et al's broader study derived a history of Antarctic sea ice for 1979-2008, based upon remotely sensed data from the NASA's Nimbus-7 SMMR and DMSP SSM/I passive microwave satallites.…”

Summer mean daily air temperature extremes in Central Spitsbergen

“…Findings of both the present study concerning summer mean daily temperature extremes and the previous study by the same author concerning winter temperatures (Bednorz 2011) correspond to the increase in daily maximum and minimum temperatures in the second half of the twentieth century proved for the Fennoscandia and Nordic Sea regions (Tuomenvirta et al 2000). They also confirm the contemporary warming in the Arctic, widely described in several studies (e.g., Brázdil 1988;Førland et al 1997;Moritz et al 2002;Comiso 2003;Polyakov et al 2003;Przybylak 2000Przybylak , 2002Przybylak , 2003Przybylak , 2007Johannesen et al 2004;Styszyńska 2005;Turner et al 2006).…”

The influence of atmospheric circulation on the spatial diversity of air temperature in the area of Forlandsundet (NW Spitsbergen) during 2010–2013

“…The rise in the Arctic air temperature in recent decades has exceeded the scale of warming observed in this region in the 1920s and 1930s (Johannessen et al, 2004;Przybylak, 2002Przybylak, , 2007Przybylak, , 2016Turner et al, 2007;Turner and Marshall, 2011). As a result, large changes in environment (e.g.…”