Seasonally resolved surface water Δ14C variability in the Lombok Strait: A coralline perspective

� 60.5%, and individual samples range from � 72% to 134%. The annual average postbomb maximum occurs in 1973 at 122%. The timing of the postbomb maximum is consistent with a primary subtropical source for the surface waters in the Indonesian seas. During the postbomb period, the coral records regular seasonal cycles of 5% to 20%. Seasonal high D 14 C occur during March–May (warm, low salinity), and low D 14 C occur in September (cool, higher salinity). The D 14 C seasonality is coherent and in phase with the seasonal D 14 C cycle observed in Makassar Strait. We estimate the influence of high D 14 C Makassar Strait (North Pacific) water flowing through the Lombok Strait using a two end-member mixing model and the seasonal extremes observed at the two sites. The percentage of Makassar Strait water varies between 16% and 70%, and between 1955 and 1990, it averages at 40%. The rich D 14 C variability has a biennial component reflecting remote equatorial Indian Ocean forcing and a component in the ENSO band, which is interpreted to reflect Pacific forcing on the D 14 C signature in