Abrupt Changes in Atmospheric Circulation During the Medieval Climate Anomaly and Little Ice Age Recorded by Sr‐Nd Isotopes in the Siple Dome Ice Core, Antarctica

Abstract

The Southern Hemisphere westerly winds (SWW; Figure 1) are central to global climate dynamics, influencing the distribution of Southern Hemisphere mid-to-high latitude sea ice, moisture, and aerosols, and driving the ventilation of the Southern Ocean, which in turn modulates global atmospheric CO 2 and temperature (Anderson et al., 2009;Burke & Robinson, 2012;Toggweiler et al., 2006). Changes in their position are thought to directly drive changes in global climate through their influence on low-to-high-latitude ocean heat transport (Denton et al., 2021). Holocene proxy records from around the Southern Hemisphere including speleothems, glacier chronologies, and lake, marine, and bog cores, show a largely coherent pattern of SWW variability that correlates with CO 2 changes recorded by ice cores (