A new paper published in the Annals of Glaciology shows Antarctic air temperatures were warmer during the early 1800’s and 1940’s in comparison to the end of the 20th century. The authors find evidence of a quasi-periodic climate cycle lasting 30-50 years, with at least 5 climate shifts over the past 350 years, the last beginning during the 1970’s.
According to the authors, “The correlation of the newly obtained record with the circulation indices of the Southern Hemisphere (SH) shows that the central Antarctic climate is mainly governed by the type of [natural] circulation in the Southern Hemisphere: under conditions of zonal circulation, negative anomalies of temperature and precipitation rate are observed, whereas the sign of the anomalies is positive during meridional circulation.”
|Brown line is air temperature anomaly for Antarctica since 1800 calculated by Schneider et al. Red line is Nov-January [summer] temperature anomalies at Antarctic Vostok station near the South Pole. Yellow line is sea surface temperatures of S Hemisphere.|
A.A. EKAYKIN, A.V. KOZACHEK, V.Ya. LIPENKOV, Yu.A. SHIBAEV
Climate and Environment Research Laboratory, Arctic and Antarctic Research Institute, St Petersburg, Russia