Central West Antarctica among the most rapidly warming regions on Earth

• Main Authors: David H. Bromwich, Julien P. Nicolas, Andrew J. Monaghan, Matthew A. Lazzara, Linda M. Keller, George A. Weidner, Aaron B. Wilson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2012
• Subjects: Amundsen Sea; Antarctic; Austral; Byrd; Byrd Station; West Antarctic Ice Sheet; West Antarctica; Antarc*; Antarctica; Ice Sheet; Ice Shelves
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.394.1974; http://cambioclimatico-bolivia.org/archivos/20130224004616_0.pdf

temperature changes in recent decades remain uncertain. West Antarctica has probably warmed since the 1950s, but there is disagreement regarding the magnitude, seasonality and spatial extent of this warming. This is primarily because long-term near-surface temperature observations are restricted to Byrd Station in central West Antarctica, a data set with substantial gaps. Here, we present a complete temperature record for Byrd Station, in which observations have been corrected, and gaps have been filled using global reanalysis data and spatial interpolation. The record reveals a linear increase in annual temperature between 1958 and 2010 by 2.4±1.2 ◦ C, establishing central West Antarctica as one of the fastest-warming regions globally. We confirm previous reports of West Antarctic warming, in annual average and in austral spring and winter, but find substantially larger temperature increases. In contrast to previous studies, we report statistically significant warming during austral summer, particularly in December–January, the peak of the melting season. A continued rise in summer temperatures could lead to more frequent and extensive episodes of surface melting of the West Antarctic Ice Sheet. These results argue for a robust long-term meteorological observation network in the region. Glacier acceleration along the Amundsen Sea coast 1 has been responsible for the increasing mass loss from the West Antarctic Ice Sheet (WAIS) in recent years 2. This has raised concerns about the present and future state of the WAIS, given its known potential instability in a warmer climate 3. Key mechanisms behind this acceleration have been identified as the melting and thinning of the floating ice shelves triggered by warm ocean water 4,5. In comparison, it is still a matter of debate whether the atmosphere above the WAIS has warmed over the past few decades, especially since the 1957–1958 International Geophysical Year, the start of