Advances in Describing Recent Antarctic Climate Variablity

Abstract

Antarctica is a challenging region for conducting meteorological research because of its geographic isolation, climate extremes, vastness, and lack of permanent human inhabitants. About 15 observing stations have been in continuous operation since the onset of the modern scientific era in Antarctica during the International Geophysical Year in 1957/58. Identifying and attributing natural- and human-caused climate change signals from the comparatively short Antarctic dataset is confounded by large year-to-year fluctuations of temperature, atmospheric pressure, and snowfall. Yet there is increasing urgency to understand Antarctica's role in the global climate system for a number of reasons, most importantly the potential consequences of ice-mass loss on global sea level rise. Here, we describe recently created records that allow Antarctic near-surface temperature and snowfall changes to be assessed in all of Antarctica's 24 glacial drainage systems during the past five decades. The new near-surface temperature and snowfall records roughly double the length of previous such datasets, which have complete spatial coverage over the continent. They indicate complex patterns of regional and seasonal climate variability. Of particular note is the occurrence of widespread positive temperature trends during summer since the 1990s, the season when melt occurs. In forthcoming years, careful monitoring of the summer trends will be required to determine whether they are associated with a natural cycle or the start of an anthropogenic warming trend. Key questions are raised during the International Polar Year.