Water-stable isotopes in polar ice cores are a widely used temperature proxy in paleoclimate reconstruction, yet calibration remains challenging in East Antarctica. Here, we reconstruct the magnitude and spatial pattern of Last Glacial Maximum surface cooling in Antarctica using borehole thermometry and firn properties in seven ice cores. West Antarctic sites cooled ~10°C relative to the preindustrial period. East Antarctic sites show a range from ~4° to ~7°C cooling, which is consistent with the results of global climate models when the effects of topographic changes indicated with ice core air-content data are included, but less than those indicated with the use of water-stable isotopes calibrated against modern spatial gradients. An altered Antarctic temperature inversion during the glacial reconciles our estimates with water-isotope observations.

极地冰芯中的水稳定同位素是古气候重建中广泛使用的温度代表，但在东南极洲校准仍然具有挑战性。在这里，我们使用钻孔温度测量法和七个冰芯中的冷杉特性重建了南极洲末次盛冰期表面冷却的幅度和空间格局。相对于工业化前时期，南极西部站点的温度降低了约 10°C。南极东部站点显示出~4° 到~7°C 的降温范围，这与包括冰芯空气含量数据指示的地形变化影响时全球气候模型的结果一致，但低于用冰芯空气含量数据指示的那些使用根据现代空间梯度校准的水稳定同位素。