Accumulation Variability in the Antarctic Peninsula: The Role of Large-Scale Atmospheric Oscillations and Their Interactions*

AbstractA new ice core drilled in 2010 to bedrock from the Bruce Plateau (BP) on the Antarctic Peninsula (AP) provides a high temporal resolution record of environmental conditions in this region. The extremely high annual accumulation rate at this site facilitates analysis of the relationships between annual net accumulation An on the BP and large-scale atmospheric oscillations. Over the last ~45 years, An on the BP has been positively correlated with both the southern annular mode (SAM) and Southern Oscillation index (SOI). Extending this analysis back to 1900 reveals that these relationships are not temporally stable, and they exhibit major shifts in the late-1940s and the mid-1970s that are contemporaneous with phase changes in the Pacific decadal oscillation (PDO). These varying multidecadal characteristics of the An–oscillation relationships are not apparent when only data from the post-1970s era are employed. Analysis of the longer ice core record reveals that the influence of the SAM on An depends...