Abrupt fluctuations in North Pacific Intermediate Water modulated changes in deglacial atmospheric CO2

• Published in: Frontiers in Marine Science
• Main Authors: Liu, Yanguang, Qiu, Yue, Li, Dongling, Artemova, Antonina V., Zhang, Yuying, Bosin, Aleksandr A., Gorbarenko, Sergey A., Liu, Qingsong, Zhao, Debo, Sha, Longbin, Zhong, Yi
• Format: Report
• Language: English
• Published: FRONTIERS MEDIA SA 2022
• Subjects: sea surface temperature; North Pacific Intermediate Water; biological productivity; CO2; subarctic Pacific Ocean; Environmental Sciences & Ecology; Marine & Freshwater Biology; Environmental Sciences; SUB-ARCTIC PACIFIC; SEA-SURFACE TEMPERATURE; NORTHWESTERN PACIFIC; SOUTHERN-OCEAN; BERING-SEA; CLIMATE VARIABILITY; TIME-SERIES; OKHOTSK SEA; SEDIMENTS; PRODUCTIVITY; Arctic; Southern Ocean; Bering Sea; Okhotsk; Pacific; Global warming; okhotsk sea; Sea ice; Subarctic
• Online Access: http://ir.qdio.ac.cn/handle/337002/180565; https://doi.org/10.3389/fmars.2022.945110

As a major reservoir of heat and CO2, the Pacific Ocean is an important component of the global climate system, but the nature of its circulation under different climatic conditions remains poorly understood. We present sedimentary records of surface water hydrography and nutrient dynamics from the subarctic Pacific Ocean, with the aim of investigating changes in sea-ice coverage, biological productivity, and sea surface temperature in the subarctic Northwest Pacific since 32 kyr. Our records indicate an enhanced North Pacific surface water stratification from the last glacial to Heinrich Stadial 1, which generally limited the siliceous productivity supply to the surface water. A productivity peak during the Bolling/Allerod warm interval was associated with an increase in the atmospheric pCO(2), and it was driven by the increased supply of nutrient- and CO2-rich waters. This process can be attributed to the collapse of the North Pacific Intermediate Water formation at the onset of the Bolling/Allerod interstadial. Moreover, a northward shift of the westerly winds and the gyre boundary could have modulated the expansion of the subpolar gyre, driving changes in poleward heat transport, biogeochemistry, and the hydroclimate of the North Pacific. Our results are consistent with modern evidence for a northward shift of the westerlies in response to global warming, which will likely result in CO2 outgassing from the subarctic Pacific Ocean in the future.