Coral record of variability in the upstream Kuroshio Current during 1953–2004
Journal
Journal of Geophysical Research: Oceans
Journal Volume
122
Journal Issue
8
Pages
6936-6946
Date Issued
2017
Author(s)
Abstract
The Kuroshio Current (KC), one of the most important western boundary currents in the North Pacific Ocean, strongly affects regional hydroclimate in East Asia and upper ocean thermal structure. Limited by few on-site observations, the responses of the KC to regional and remote climate forcings are still poorly understood. Here we use monthly coral δ18O data to reconstruct a KC transport record with annual to interannual resolution for the interval 1953–2004. The field site is located in southern Taiwan on the western flank of the upstream KC. Increased (reduced) KC transport would generate strong (weak) upwelling, resulting in relatively high (low) local coral δ18O. The upstream KC transport and downstream transport, off Tatsukushi Bay, Japan, covary on interannual and decadal time scales. This suggests common forcings, such as meridional drift of the North Equatorial Current bifurcation, or zonal climatic oscillations in the Pacific. The intensities of KC transport off southeastern and northeastern Taiwan are in phase before 1990 and antiphase after 1990. This difference may be due to a poleward shift of the subtropical western boundary current as a response to global warming. © 2017. American Geophysical Union. All Rights Reserved.
Subjects
coral; ENSO; geochemistry; global warming; Kuroshio Current; PDO
Other Subjects
biogeochemistry; climate forcing; climate oscillation; coral record; current direction; El Nino-Southern Oscillation; global warming; hydrometeorology; thermal structure; western boundary current; Far East; Japan; Kuroshio Current; North Equatorial Current; Pacific Ocean; Pacific Ocean (North); Taiwan; Anthozoa
Type
journal article