Synoptic-scale controls on the δ18O in precipitation across Beringia

Bailey, Hannah L.; Kaufman, Darrell S.; Henderson, Andrew C.G.; Leng, Melanie J. ORCID: https://orcid.org/0000-0003-1115-5166. 2015 Synoptic-scale controls on the δ18O in precipitation across Beringia. Geophysical Research Letters, 42 (11). 4608-4616. https://doi.org/10.1002/2015GL063983

Before downloading, please read NORA policies.

Preview

Text
grl52997.pdf - Accepted Version
Download (1MB) | Preview

Official URL: http://dx.doi.org/10.1002/2015GL063983

Abstract/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.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1002/2015GL063983
ISSN:	00948276
Date made live:	20 May 2015 13:55 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/510853

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1002/2015GL063983

ISSN:

00948276

Date made live:

20 May 2015 13:55 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/510853