Search Results

You are looking at 1 - 1 of 1 items for :

  • Author or Editor: Anton Seimon x
  • Journal of Hydrometeorology x
  • All content x
Clear All Modify Search
Heather Guy, Anton Seimon, L. Baker Perry, Bronwen L. Konecky, Maxwell Rado, Marcos Andrade, Mariusz Potocki, and Paul A. Mayewski

Abstract

The tropical Andes of southern Peru and northern Bolivia have several major mountain summits suitable for ice core paleoclimatic investigations. However, incomplete understanding of the controls on the isotopic (δD, δ 18O) composition of precipitation and a paucity of field observations in this region continue to limit ice-core-based paleoclimate reconstructions. This study examines four years of daily observations of δD and δ 18O in precipitation from a citizen scientist network on the northeastern margin of the Altiplano, to identify controls on the subseasonal spatiotemporal variability in δ 18O during the wet season (November–April). These data provide new insights into modern δ 18O variability at high spatial and temporal scales. We identify a regionally coherent subseasonal signal in precipitation δ 18O featuring alternating periods of high and low δ 18O of 9–27-day duration. This signal reflects variability in precipitation delivery driven by synoptic conditions and closely relates to variations in the strength of the South American low-level jet and moisture availability over the study area. The annual layer of snowpack on the Quelccaya Ice Cap observed in the subsequent dry season retains this subseasonal signal, allowing the development of a snow-pit age model based on precipitation δ 18O measurements, and demonstrating how synoptic variability is transmitted from the atmosphere to mountaintop snowpacks along the Altiplano’s eastern margin. This result improves our understanding of the hydrometeorological processes governing δ 18O and δD in tropical Andean precipitation and has implications for improving paleoclimate reconstructions from tropical Andean ice cores and other paleoclimate records.

Full access