Dynamic millennial-scale climate changes in the northwestern Pacific over the past 40,000 years
Journal
Geophysical Research Letters
Journal Volume
37
Journal Issue
23
Date Issued
2010
Author(s)
Chen, M.-T.
Lin, X.P.
Chang, Y.-P.
Chen, Y.-C.
Lo, L.
Shen, C.-C.
Yokoyama, Y.
Oppo, D.W.
Thompson, W.G.
Zhang, R.
Abstract
Ice core records of polar temperatures and greenhouse gases document abrupt millennial-scale oscillations that suggest the reduction or shutdown of thermohaline Circulation (THC) in the North Atlantic Ocean may induce the abrupt cooling in the northern hemisphere. It remains unknown, however, whether the sea surface temperature (SST) is cooling or warming in the Kuroshio of the Northwestern Pacific during the cooling event. Here we present an AMS 14C-dated foraminiferal Mg/Ca SST record from the central Okinawa Trough and document that the SST variations exhibit two steps of warming since 21 ka at 14.7 ka and 12.8 ka, and a cooling (∼1.5C) during the interval of the Younger Dryas. By contrast, we observed no SST change or oceanic warming (∼1.5-2C) during the episodes of Northern Hemisphere cooling between ∼21-40 ka. We therefore suggest that the Antarctic-like timing and amplitude of millennial-scale SST variations in the subtropical Northwestern Pacific between 20-40 ka may have been determined by rapid ocean adjustment processes in response to abrupt wind stress and meridional temperature gradient changes in the North Pacific. © 2010 by the American Geophysical Union.
SDGs
Other Subjects
Atmospheric temperature; Global warming; Greenhouse gases; Ocean currents; Ice core records; Kuroshio; Meridional temperature gradient; North Atlantic Ocean; North Pacific; Northern Hemispheres; Okinawa Trough; Polar temperature; Sea surface temperatures; Thermohaline circulations; Younger Dryas; Glacial geology; calcium; carbon isotope; climate change; foraminifera; greenhouse gas; ice core; long-term change; magnesium; Northern Hemisphere; paleoceanography; polar meteorology; sea surface temperature; temperature gradient; thermohaline circulation; warming; wind stress; Younger Dryas; Atlantic Ocean; Atlantic Ocean (North); East China Sea; Kuroshio Current; Okinawa Trough; Pacific Ocean
Type
journal article