Wu, YangFallon, Stewart2022-07-262169-9275http://hdl.handle.net/1885/269943Compared to the natural production of 14C, thermonuclear tests have produced a globally abnormal 14C signal. To examine and reconstruct ocean circulation in the South China Sea (SCS), we generated a prebomb to postbomb 14C time series from a Porites lobata coral from the west side of Palawan Island, Philippines. Results show a diluted early bomb 14C intrusion in late 1955. We use this record to extend our understanding of the surface ocean circulation in and around the SCS by tracing 14C labeled water from nuclear test sites. Our postbomb 14C peaked at 154% in 1975, which lags 10 years from the atmospheric peak, consistent with other marine records. This coral record also displayed clear seasonal 14C cycles indicating different surface waters passed the Palawan Island coral site due to seasonal variations of the East Asian Monsoon.We thank Bob Halley and Ryan Moyerfrom the USGS for providing this coralto S.F. Y.W. is supported by ANU PhDScholarship and ANU SupplementaryScholarship. Funding for the projectwas provided by the ANU RadiocarbonLaboratory. The detailed comments andsuggestions from T. P. Guilderson andone anonymous reviewer significantlyimproved the original manuscript.application/pdfen-AU© 2020 The authors202010.1029/2019JC0159792021-08-01