Hydroclimate records from the eastern tropical Indian Ocean of sediment core SO189-39KL

Planktic foraminiferal oxygen isotopes, Mg/Ca and Mg/Ca-derived SST estimates of sediment core SO189/2_039KL. The isotopic composition of the samples was measured using a Finnigan MAT 251 mass spectrometer, which is connected with automatic lines for carbonate preparation. For all stable isotope measurements, a working standard was used, which has been calibrated against VPDB (Vienna Pee Dee Belemnite) by using the NBS 19 standard. The long‐term analytical standard deviation is about ±0.07‰ (Isotope Laboratory at Faculty of Geosciences, University of Bremen). For Mg/Ca analysis, samples were cleaned by applying a slight modification of the method originally proposed by Barker et al. (2003). Mg/Ca measurements were performed at MARUM, University of Bremen, using a Perkin ElmerOptima 3300 R inductively coupled plasma optical emission spectrophotometer (ICP-OES) equipped with an autosampler and a U-5000 AT ultrasonic nebulizer (Cetac Technologies). Mg/Ca ratios were converted to temperature following the multispecies Mg/Ca-temperature calibration of Anand et al. (2003; doi:10.1029/2002PA000846). To calculate the δ18O of seawater, the δ18O:temperature equation of Bemis et al. (1998; doi:10.1029/98PA00070) was used. The values were then converted to standard mean ocean water (SMOW) by adding 0.27% and corrected for sea-level changes following Waelbroeck et al. (2002; doi:10.1016/S0277-3791(01)00101-9).