Synoptic-scale controls on the δ18O in precipitation across Beringia

Oxygen isotope records of precipitation (δ18Oprecip) from Beringia are thought to reflect synoptic-scale circulation changes associated with the Aleutian Low. To delineate the spatial pattern of δ18Oprecip associated with the two dominant modes of Aleutian Low circulation, we combine modern δ18Oprec...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Bailey, Hannah L., Kaufman, Darrell S., Henderson, Andrew C.G., Leng, Melanie J.
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2015
Subjects:
Pacific
aleutian low
Aleutian Islands
Beringia
Online Access:http://nora.nerc.ac.uk/id/eprint/510853/
https://nora.nerc.ac.uk/id/eprint/510853/1/grl52997.pdf
https://doi.org/10.1002/2015GL063983
Description
Summary:Oxygen isotope records of precipitation (δ18Oprecip) from Beringia are thought to reflect synoptic-scale circulation changes associated with the Aleutian Low. To delineate the spatial pattern of δ18Oprecip associated with the two dominant modes of Aleutian Low circulation, we combine modern δ18Oprecip and deuterium excess data with climate reanalysis and back-trajectory modelling. Aleutian Low strength and position are revealed to systematically affect regional moisture source and δ18Oprecip; whereby a strengthened Aleutian Low causes lower (higher) δ18Oprecip in western (eastern) Beringia. We compare a new 100-year-long δ18O record from the Aleutian Islands with the North Pacific Index, the primary indicator of Aleutian Low strength, and find a significant positive relationship (r = 0.43, p < 0.02, n = 28) that tracks late 20th century change. This study demonstrates synoptic-scale circulation controls on our isotope record, and provides a coherent framework for interpreting existing and emerging paleo-isotope data from the region.

Similar Items