Terciopelo Cave, Costa Rica Speleothem Oxygen Isotope Data Lachniet, M.S.; Johnson, L.; Asmerom, Y.; Burns, S.J.; Polyak, V.J.; Patterson, W.P.; Burt, L.; Azouz, A. Lachniet, M.S. Johnson, L. Asmerom, Y. Burns, S.J. Polyak, V.J. Patterson, W.P. Burt, L. Azouz, A. Intertropical Convergence Zone (ITCZ) earth science/paleoclimate/speleothems (delta 18O,calcium carbonate,null,per mil VPDB,null,speleothems,composited,isotope ratio mass spectrometry,N,Spliced record from three cores with 100-year interpolation) earth science/paleoclimate/speleothems (age,null,null,calendar year before present,null,speleothems,null,null,N,present defined as 2008 CE) earth science/paleoclimate/speleothems (delta 18O,calcium carbonate,null,per mil VPDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems (Terciopelo Cave>LATITUDE 10.1667>LONGITUDE -85.3333) We present a high-resolution terrestrial archive of Central American rainfall over the period 100-24 and 8.1-6.5 ka, based on d18O time series from U-series dated stalagmites collected from a cave on the Pacific Coast of Costa Rica. Our results indicate substantial d18O variability on millennial to orbital time scales that is interpreted to reflect rainfall variations over the cave site. Correlations with other paleoclimate proxy records suggest that the rainfall variations are forced by sea surface temperatures (SST) in the Atlantic and Pacific Oceans in a fashion analogous to the modern climate cycle. Higher rainfall is associated with periods of a warm tropical North Atlantic Ocean and large SST gradients between the Atlantic and Pacific Oceans. Rainfall variability is likely linked to the intensity and/or latitudinal position of the intertropical convergence zone (ITCZ). Periods of higher rainfall in Costa Rica are also associated with an enhanced sea surface salinity gradient on either side of the isthmus, suggesting greater freshwater export from the Atlantic Basin when the ITCZ is stronger and/or in a more northerly position. Further, wet periods in Central America coincide with high deuterium excess values in Greenland ice, suggesting a direct link between low latitude SSTs, tropical rainfall, and moisture delivery to Greenland. Our results indicate that a stronger tropical hydrological cycle during warm periods and large inter-ocean SST gradients enhanced the delivery of low latitude moisture to Greenland. STUDY NOTES: Stalagmite stable oxygen isotope values from Barra Honda National Park, Costa Rica, over 98 to 24 ka and 8.0 to 6.6 ka. In this tropical location, rainfall d18O values are inversely correlated with rainfall amount at and upwind of the sampling location, so the stalagmite d18O data are interpreted as a paleorainfall proxy record. We analyzed 1684 d18O subsamples at the Universities of Massachusetts and Saskatchewan, and at the Las Vegas Isotope Science Laboratory at the University of Nevada, Las Vegas. Stalagmites CT-5, CT-6, and CT-7 were subsampled for stable isotopes at a 1.0 mm interval, whereas CT-1 was subsampled every 0.5 mm. Samples were analyzed on ThermoElectron Delta + or Delta V mass spectrometers in Kiel III and IV automated carbonate preparation devices, where samples were reacted with phosphoric acid at 70°C to liberate CO2 gas. Values are reported as ‰ relative to the VPDB standard via regular calibration to an internal laboratory standard. Precision is better than 0.06‰ for d18O. A composite time series was created from stalagmites CT-1, -5, and -6 by splicing together the three records. The time series was then interpolated at a 100 year interval. The d18O data in this file for the spliced CT-1, CT-5, and CT-6 stalagmites are raw values, not corrected for change in d18O of ocean. Ages are in yr BP, where BP is time of U-series analysis of A.D. 2008. The stalagmites were recovered from Barra Honda National Park, on the Nicoya Peninsula, Pacific Coast of Costa Rica. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Lachniet, M.S. Investigator : Johnson, L. Investigator : Asmerom, Y. Investigator : Burns, S.J. Investigator : Polyak, V.J. Investigator : Patterson, W.P. Investigator : Burt, L. Investigator : Azouz, A. 2010-07-09 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/10442 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.xls https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.xls https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.txt English https://www.ncdc.noaa.gov/paleo/study/10442 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.xls https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/northamerica/costa-rica/terciopelo2009.txt Lachniet, M.S., L. Johnson, Y. Asmerom, S.J. Burns, V. Polyak, W.P. Patterson, L. Burt, and A. Azouz. 2009. Late Quaternary moisture export across Central America and to Greenland: evidence for tropical rainfall variability from Costa Rican stalagmites. Quaternary Science Reviews, Vol. 28, pp. 3348-3360. doi:10.1016/j.quascirev.2009.09.018 START YEAR: 98250 cal yr BP * END YEAR: 6560 cal yr BP -85.3333 10.1667 -85.3333 10.1667