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Interannual Coral Δ 14 C Records of Surface Water Exchange Across the Luzon Strait
Author(s) -
Ramos R. D.,
Goodkin N. F.,
Druffel E. R. M.,
Fan T. Y.,
Siringan F. P.
Publication year - 2019
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2018jc014735
Subject(s) - oceanography , outflow , geology , pacific ocean , intrusion , monsoon , climatology , pacific decadal oscillation , seawater , sea surface temperature , geochemistry
The Luzon Strait (LS) hosts the largest transport of water between the Western Pacific Ocean (WPO) and the South China Sea (SCS). The transport through the strait, dominated by the westward propagation of the Kuroshio Intrusion, influences the climate and circulation of the SCS. While numerical models have investigated the interannual variability of the transport and subsequent water exchange across the LS, a lack of long‐term on‐site records prevents a general consensus on the transport rates, variability, and drivers. Corals offer high‐resolution, continuous histories of radiocarbon (Δ 14 C) content of the seawater dissolved inorganic carbon, allowing us to track changes in ocean transport and circulation through time. Seasonal and annual Δ 14 C samples from Houbihu, Taiwan, and Palaui, Philippines, located on either side of the strait, are compared to the Western Pacific Ocean and SCS Δ 14 C records to examine the spatial and temporal Δ 14 C variability in the region. We calculated the mean transport across the strait using a five‐box mixing model and identified its potential drivers. The mean amount of water exchanged across the strait from 1970 to 1999 was 2.2 Sv, ranging from −13.4 to 16 Sv, where a positive (negative) value indicates net flow into (out of) the SCS. A weaker East Asian Winter Monsoon increases the contribution of the SCS outflow on the Kuroshio Intrusion‐dominated LS, while the El Niño–Southern Oscillation primarily drives the intrusion into the SCS. These results provide support to the dominant control of El Niño–Southern Oscillation on the long‐term ocean circulation variability in this region.