Atmospheric Dust Transport to High‐Elevation Dronning Maud Land, Antarctica, Modulated by Cyclonic Circulation, the Pacific Decadal Oscillation, and Source Emissions

The dependence of aeolian dust transport on atmospheric circulation patterns allows dust preserved in Antarctic ice cores to serve as a proxy for past circulation variability. Here, we investigate dust transport to high-elevation Dronning Maud Land (DML) in Antarctica through analysis of the 1300-year-old ISOL-ICE ice core dust record together with modeled dust transport to high-elevation DML and Pearson correlation analysis with atmospheric reanalysis data and climate indices. The ice core dust record reveals an abrupt increase in dust deposition and particle size from 1915 to 2017 relative to pre-1915 values. Dust flux increased 10, 5, and 3-fold for bulk (0.9–50 μm diameter particles), 0.9–10 μm, and 0.9–5 μm particles, respectively, while the volume fraction of 2–5 μm particles within the 0.9–5 μm range increased by 12%. Interannual correlations show that cyclonic activity south of South America, associated with the Pacific Decadal Oscillation (PDO), is the dominant identified mechanism by which dust is transported from southern South America to high-elevation DML, explaining 10%–36% of variability in dust deposition at the ice core site. The abrupt dust increase is best explained by enhanced dust emissions dominantly in southern South America related to rapid land use change, with some contribution from local Antarctic sources, both occurring within variability of cyclonic circulation south of South America and the PDO. These findings suggest that future dust transport to high-elevation DML will likely be strongly modulated by emissions, the PDO, and cyclonic activity in southern South America.