Drivers of δ¹⁸O variability preserved in ice cores from Earth’s highest tropical mountain

Plain Language Summary - The oxygen stable isotope records (δ¹⁸O) of the new Huascarán ice cores (collected in 2019 from Peru) are a natural archive of tropical Pacific climate and hydrological conditions over the Amazon Basin. This is evidenced by strong correlations between δ¹⁸O and spatiotemporal sea surface temperature (SST) and precipitation data sets that cover the most recent 60 years of the ice core records. Additionally, the Huascarán δ¹⁸O records are significantly related to temperatures in the upper atmosphere, suggesting that temperature may also play a critical role in modifying the isotope values. The statistical significance of each of these relationships has also been increasing over the last 60 years, and the rates of increase are greatest between the δ¹⁸O records from the higher elevation ice core site and the temperature-related climate data sets. This suggests that the isotope records from the Huascarán Summit (6,768 masl) are more sensitive to large-scale changes in temperature than the isotope records on the Huascarán Col (6,050 masl). This is the first study to examine ice core records from the Summit of Earth’s highest tropical mountain and offers valuable insights into the behavior of δ¹⁸O in the tropical Andes.

Recommended citation: Weber, A. M., Thompson, L. G., Davis, M., Mosley-Thompson, E., Beaudon, E., Kenny, D., Lin, P.-N., and Sierra-Hernández, M. R. (2023). Drivers of δ¹⁸O variability preserved in ice cores from Earth's highest tropical mountain. Journal of Geophysical Research: Atmospheres. 128(19). DOI:10.1029/2023JD039006