High- and low-latitude forcings drive Atacama Desert rainfall variations over the past 16,000 years

Late Quaternary precipitation dynamics in the central Andes have been linked to both high- and low-latitude atmospheric teleconnections. We use present-day relationships between fecal pellet diameters from ashy chinchilla rats (Abrocoma cinerea) and mean annual rainfall to reconstruct the timing and magnitude of pluvials (wet episodes) spanning the past 16,000 years in the Atacama Desert based on 81 C-14-dated A. cinerea paleomiddens. A transient climate simulation shows that pluvials identified at 15.9 to 14.8, 13.0 to 8.6, and 8.1 to 7.6 ka B.P. can be linked to North Atlantic (high-latitude) forcing (e. g., Heinrich Stadial 1, Younger Dryas, and Bond cold events). Holocene pluvials at 5.0 to 4.6, 3.2 to 2.1, and 1.4 to 0.7 ka B.P. are not simulated, implying low-latitude internal variability forcing (i.e., ENSO regime shifts). These results help constrain future central Andean hydroclimatic variability and hold promise for reconstructing past climates from rodent middens in desert ecosystems worldwide.

Automated summary

Late Quaternary precipitation dynamics in the central Andes are influenced by high- and low-latitude atmospheric teleconnections. By studying the relationship between fecal pellet diameters from ashy chinchilla rats and mean annual rainfall, researchers reconstructed pluvials in the Atacama Desert over the past 16,000 years and identified different influences on wet episodes from North Atlantic forcing to low-latitude ENSO regime shifts. This study provides insights into future hydroclimatic variability in the central Andes and offers potential for reconstructing past climates using rodent middens in desert ecosystems worldwide.