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 modeling. 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 twentieth century change. This study demonstrates synoptic-scale circulation controls on our isotope record and provides a coherent framework for interpreting existing and emerging paleoisotope data from the region.
- Aleutian Low
- North Pacific Index
- oxygen isotopes
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)