Antarctic climate change during the last 50 years

Abstract

The Reference Antarctic Data for Environmental Research (READER) project data set of monthly mean Antarctic nearsurface temperature, mean sea-level pressure (MSLP) and wind speed has been used to investigate trends in these quantities over the last 50 years for 19 stations with long records. Eleven of these had warming trends and seven had cooling trends in their annual data (one station had too little data to allow an annual trend to be computed), indicating the spatial complexity of change that has occurred across the Antarctic in recent decades. The Antarctic Peninsula has experienced a major warming over the last 50 years, with temperatures at Faraday/Vernadsky station having increased at a rate of 0.56°C decade −1 over the year and 1.09°C decade −1 during the winter; both figures are statistically significant at less than the 5% level. Overlapping 30 year trends of annual mean temperatures indicate that, at all but two of the 10 coastal stations for which trends could be computed back to 1961, the warming trend was greater (or the cooling trend less) during the 1961-90 period compared with 1971-2000. All the continental stations for which MSLP data were available show negative trends in the annual mean pressures over the full length of their records, which we attribute to the trend in recent decades towards the Southern Hemisphere annular mode (SAM) being in its high-index state. Except for Halley, where the trends are constant, the MSLP trends for all stations on the Antarctic continent for 1971-2000 were more negative than for 1961-90. All but two of the coastal stations have recorded increasing mean wind speeds over recent decades, which is also consistent with the change in the nature of the SAM.

An Arctic and antarctic perspective on recent climate change

“…. These observations were used to assess the change in near-surface conditions across the Antarctic over roughly the last 50 years (Turner et al, 2005). The seasonal and annual temperature trends are summarized for 15 stations in Figure 11.…”

“…Figure 11 shows that beyond the Antarctic Peninsula there were few statistically significant temperature changes in recent decades. In fact, of the 19 stations with long records examined by Turner et al (2005), 11 had warming trends in their annual data and 7 had cooling, with 1 station having too little data to allow the computation of an annual trend. An exception is the Amundsen-Scott station at the South Pole, which has experienced a cooling in all seasons, although only the annual trend of −0.17°C per decade is statistically significant at the 10% level.…”

Advection in polar and sub-polar environments: Impacts on high latitude marine ecosystems

“…Increased intensity of the Amundsen Sea Low over recent decades has been associated with Antarctic-wide atmospheric changes that relate to the formation of the ozone hole Fogt and Zbacnik, 2014), and has dominated changes in wind stress across the region. Lower ozone concentrations over recent decades have been linked to summer strengthening (of $15-20%) of the large-scale clockwise winds, which have acted to further isolate Antarctica atmospherically (Turner et al, 2005a(Turner et al, , 2005b. This strengthening of the westerlies (Marshall et al, 2006) is demonstrated by changes in the Southern Annular Mode index, which is a measure of the principal mode of variability in the atmospheric circulation of the Southern Hemisphere (Fig.7).…”

“…et al, 2008b). This strengthening of the westerlies has contributed to cooling air temperatures over eastern Antarctica and the Antarctic plateau, but warming over the Antarctic Peninsula (Thompson and Solomon, 2002;Turner et al, 2005aTurner et al, , 2005bStammerjohn et al, 2008b). Regional warming in western Antarctica has also been linked to increased sea surface temperatures in the tropical Pacific that generate long, quasi-stationary atmospheric waves (Rossby waves), leading to southward advection of warm air associated with the Pacific South America Mode towards the west coast of Antarctica (Stammerjohn et al, 2008a;Ding et al, 2011).…”

Climate Change: Evidence of Human Causes and Arguments for Emissions Reduction

“…If the surrounding oceans warm enough, then WAIS could rapidly disintegrate. Meanwhile, the Antarctic Peninsula, home to the northernmost fringes of WAIS, is undergoing perhaps the largest increase in temperature of any location on the planet (King et al, 2002;Turner et al, 2005), and there are already some warning signs that a WAIS collapse could be in progress. 3 Thus, abrupt WAIS collapse is a major cause for concern.…”