Abstract
We provide the first comprehensive analysis of the relationships between large‐scale patterns of Southern Hemisphere climate variability and the detailed structure of Antarctic precipitation. We examine linkages between the high spatial resolution precipitation from a regional atmospheric model and four patterns of large‐scale Southern Hemisphere climate variability: the southern baroclinic annular mode, the southern annular mode, and the two Pacific‐South American teleconnection patterns. Variations in all four patterns influence the spatial configuration of precipitation over Antarctica, consistent with their signatures in high‐latitude meridional moisture fluxes. They impact not only the mean but also the incidence of extreme precipitation events. Current coupled‐climate models are able to reproduce all four patterns of atmospheric variability but struggle to correctly replicate their regional impacts on Antarctic climate. Thus, linking these patterns directly to Antarctic precipitation variability may allow a better estimate of future changes in precipitation than using model output alone.
Highlights
Model projections of future climate indicate that Antarctic precipitation is likely to increase over the remainder of the 21st century (e.g., Frieler et al, 2015; Ligtenberg et al, 2013; Palerme et al, 2016), as the air masses that deliver the majority of snow to the continent become warmer and able to increase their capacity to retain moisture
We provide the first comprehensive analysis of the relationships between large-scale patterns of Southern Hemisphere climate variability and the detailed structure of Antarctic precipitation
To provide physical context for the linkages between large-scale climate variability and Antarctic precipitation, we first explore the differences in the 850 hPa meridional moisture flux and near-surface winds between the positive and negative polarities of the four patterns of atmospheric variability
Summary
Model projections of future climate indicate that Antarctic precipitation is likely to increase over the remainder of the 21st century (e.g., Frieler et al, 2015; Ligtenberg et al, 2013; Palerme et al, 2016), as the air masses that deliver the majority of snow to the continent become warmer and able to increase their capacity to retain moisture. This will act to partially counteract the expected rise in global sea level due to thermal expansion and loss of terrestrial ice. despite its importance in the Earth system, a lack of direct observations have meant that Antarctic precipitation is relatively poorly constrained. Frieler et al (2015) used ice-core data and model palaeo- and future-climate simulations to derive a continent-scale increase in accumulation of ~5 ± 1% KÀ1
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