Panama Basin 27,000 Year Alkenone dD Data Pahnke, K.; Sachs, J.P.; Keigwin, L.D.; Timmermann, A.; Xie, S.-P. Pahnke, K. Sachs, J.P. Keigwin, L.D. Timmermann, A. Xie, S.-P. hydrology earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (alkenone,sediment,null,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 2H,alkenone,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 2H,alkenone,one standard deviation,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (alkenone unsaturation index Uk37 prime,null,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (KN176-2-MC14>LATITUDE 5.8468>LONGITUDE -77.6142) (KN176-2-MC33>LATITUDE 4.665>LONGITUDE -77.9633) (KN176-2-JPC32>LATITUDE 4.6665>LONGITUDE -77.9633) The tropical Pacific plays a central role in the climate system by providing large diabatic heating that drives the global atmospheric circulation. Quantifying the role of the tropics in late Pleistocene climate change has been hampered by the paucity of paleoclimate records from this region and the lack of realistic transient climate model simulations covering this period. Here we present records of hydrogen isotope ratios (dD) of alkenones from the Panama Basin off the Colombian coast that document hydrologic changes in equatorial South America and the eastern tropical Pacific over the past 27,000 years (a) and the past 3 centuries in detail. Comparison of alkenone dD values with instrumental records of precipitation over the past ~100 a suggests that dD can be used as a hydrologic proxy. On long timescales our records indicate reduced rainfall during the last glacial period that can be explained by a southward shift of the mean position of the Intertropical Convergence Zone and an associated reduction of Pacific moisture transport into Colombia. Precipitation increases at ~17 ka in concert with sea surface temperature (SST) cooling in the North Atlantic and the eastern tropical Pacific. A regional coupled model, forced by negative SST anomalies in the Caribbean, simulates an intensification of northeasterly trade winds across Central America, increased evaporative cooling, and a band of increased rainfall in the northeastern tropical Pacific. These results are consistent with the alkenone SST and dD reconstructions that suggest increasing precipitation and SST cooling at the time of Heinrich event 1. STUDY NOTES: Hydrogen isotope ratios (dD) of alkenones from 3 cores collected in the Panama Basin in the eastern tropical Pacific for the past 27,000 years. Alkenone dD values document hydrologic changes in equatorial South America and the eastern tropical Pacific. Alkenone SST's calculated using the calibration of Prahl et al., GCA 1988. core locations: KN176-2 JPC32: 4°39.99N, 77°57.80W, 2200m water depth KN176-2 MC14: 4°50.81N, 77°36.85W, 884m water depth KN176-2 MC33: 4°39.99N, 77°57.80W, 2200m water depth NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Pahnke, K. Investigator : Sachs, J.P. Investigator : Keigwin, L.D. Investigator : Timmermann, A. Investigator : Xie, S.-P. 2012-05-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12916 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.txt English https://www.ncdc.noaa.gov/paleo/study/12916 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/pahnke2007/pahnke2007.txt Pahnke, K., J.P. Sachs, L. Keigwin, A. Timmermann, and S.-P. Xie. 2007. Eastern tropical Pacific hydrologic changes during the past 27,000 years from D/H ratios in alkenones. Paleoceanography, Vol. 22, PA4214, 15 PP. doi:10.1029/2007PA001468 START YEAR: 27090 cal yr BP * END YEAR: -30 cal yr BP -77.9633 4.665 -77.6142 5.8468