Bioproductivity Changes at Low and High Latitudes of the Pacific as a Response to Reorganization of Oceanic Circulation during Termination I

详细

Our new and previously published data on sea surface bioproductivity changes from different parts of the Pacific Ocean in the Northern Hemisphere were analyzed in relation to meridional overturning circulation during the last deglaciation. Synchronous episodes of upwelling intensification in the Eastern Equatorial Pacific and Southern Ocean cores indicate that millennial-scale sea-surface bioproductivity changes reflect climatic teleconnection between these two regions by means of “oceanic tunnelling.” In the North Pacific, postglacial bioproductivity changes are in line with climate oscillations recorded in the North Greenland Ice Core and transferred to the North Pacific via the atmospheric bridge. However, in the western Bering Sea, breakdown of stratification, CO₂ release into the atmosphere and sea-surface bioproductivity rise occurred immediately at the onset of Heinrich I (~17.5–17.0 kyr BP). This might result from upwelling of southern-sourced deep water. The upwelling has been developed in the Subarctic Pacific approximately 1000–1500 years later than in the Southern Ocean. This lag likely reflects the duration of signal transferring from the high latitudes of the Southern Hemisphere to the North Pacific.