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 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.
Schneider
David P
DP
Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO 80307, USA. dschneid@ucar.edu
Steig
Eric J
EJ
D000864:Antarctic Regions; D002980:Climate; D046448:Ice Cover; D013696:Temperature