Ice cores record significant 1940s Antarctic warmth related to tropical climate variability

Although the 20th Century warming of global climate is well known, climate change in the high-latitude Southern Hemisphere (SH), especially in the first half of the century, remains poorly documented. We present a composite of water stable isotope data from high-resolution ice cores from the West An...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences
Main Authors: Schneider, David P., Steig, Eric J.
Format: Text
Language:English
Published: National Academy of Sciences 2008
Subjects:
Online Access:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2527881
http://www.ncbi.nlm.nih.gov/pubmed/18697932
https://doi.org/10.1073/pnas.0803627105
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Summary:Although the 20th Century warming of global climate is well known, climate change in the high-latitude Southern Hemisphere (SH), especially in the first half of the century, remains poorly documented. We present a composite of water stable isotope data from high-resolution ice cores from the West Antarctic Ice Sheet. This record, representative of West Antarctic surface temperature, shows extreme positive anomalies in the 1936–45 decade that are significant in the context of the background 20th Century warming trend. We interpret these anomalies—previously undocumented in the high-latitude SH—as indicative of strong teleconnections in part driven by the major 1939–42 El Niño. These anomalies are coherent with tropical sea-surface temperature, mean SH air temperature, and North Pacific sea-level pressure, underscoring the sensitivity of West Antarctica's climate, and potentially its ice sheet, to large-scale changes in the global climate.