Coupled impacts of atmospheric circulation and sea-ice on late Pleistocene terrigenous sediment dynamics in the subarctic Pacific Ocean

• Main Author: Zhong, Yi
• Format: Text
• Language: unknown
• Published: Zenodo 2021
• Subjects: Bering Sea; Pacific; aleutian low; Sea ice; Subarctic
• Online Access: https://dx.doi.org/10.5281/zenodo.5111468; https://zenodo.org/record/5111468

Processes controlling environmental change in the subarctic Pacific Ocean on millennial-to-orbital timescales are not well understood. Here we use a 230-kyr sedimentary record from the northwest Pacific Ocean to assess the response of late Pleistocene sediment dynamics to orbital forcing. Combining a source-to-sink perspective based on sedimentological records with climate model reanalysis, we reveal that fluctuations in sediment provenance were closely linked to obliquity-forced changes in atmospheric circulation modes. Specifically, the position of the Aleutian Low controlled sediment transport from the Bering Sea and Aleutian arc sources. Furthermore, a distinct shift in North Pacific ocean circulation during the Last Glacial Maximum may have been related to a strengthened Siberian High. The coincidence of atmospheric mode switches with changes in sea-ice extent and North Pacific Intermediate Water formation in the marginal seas, suggests such coupled ocean-atmosphere system as a amplifier for the regional climate variability from global background.