Absence of Elevation-Dependent Warming in Antarctica Inferred From Blue Ice Paleoclimate Records

Abstract

Reconstructing the past Antarctic climate commonly involves deep drilling of ice cores. However, the ∼1% of the Antarctic ice sheet surface covered with blue ice also provides unique, yet largely unexploited paleoclimatic opportunities. Here, we analyze 444 ice samples collected in blue ice surfaces located around the Sør Rondane Mountains. Isotope measurements (δ¹⁸O) on these samples enable us to estimate surface paleotemperatures for both the current interglacial period and the Last Glacial Maximum. Combining these paleotemperatures with the spatially varying source elevation of the sampled blue ice provides new insights on the (lack of) lapse rate evolution (i.e., changes in the elevation-temperature relationship) outside the 40°N–40°S latitudinal band. This result contrasts with low-latitude areas that have experienced elevation-dependent warming (EDW) during this period. Our results hint at a future (lack of) EDW in Antarctica, thereby highlighting the potential of blue ice area paleoclimatic archives to better predict future climatic changes.