Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability

• Published in: The Cryosphere
• Main Authors: J. Fyke, J. T. M. Lenaerts, H. Wang
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2017
• Subjects: geo; envir; Antarctic; The Antarctic; Antarc*; Antarctica; ice core; Ice Sheet; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-11-2595-2017; https://www.the-cryosphere.net/11/2595/2017/tc-11-2595-2017.pdf; https://doaj.org/article/010d4849662440a28a1d0e602fdcf491

Annually averaged precipitation in the form of snow, the dominant term of the Antarctic Ice Sheet surface mass balance, displays large spatial and temporal variability. Here we present an analysis of spatial patterns of regional Antarctic precipitation variability and their impact on integrated Antarctic surface mass balance variability simulated as part of a preindustrial 1800-year global, fully coupled Community Earth System Model simulation. Correlation and composite analyses based on this output allow for a robust exploration of Antarctic precipitation variability. We identify statistically significant relationships between precipitation patterns across Antarctica that are corroborated by climate reanalyses, regional modeling and ice core records. These patterns are driven by variability in large-scale atmospheric moisture transport, which itself is characterized by decadal- to centennial-scale oscillations around the long-term mean. We suggest that this heterogeneity in Antarctic precipitation variability has a dampening effect on overall Antarctic surface mass balance variability, with implications for regulation of Antarctic-sourced sea level variability, detection of an emergent anthropogenic signal in Antarctic mass trends and identification of Antarctic mass loss accelerations.