FN Archimer Export Format PT J TI Late Quaternary moisture export across Central America and to Greenland: evidence for tropical rainfall variability from Costa Rican stalagmites BT AF LACHNIET, Matthew S. JOHNSON, Leah ASMEROM, Yemane BURNS, Stephen J. POLYAK, Victor PATTERSON, William P. BURT, Lindsay AZOUZ, April AS 1:1;2:2;3:2;4:3;5:2;6:4;7:1;8:1; FF 1:;2:;3:;4:;5:;6:;7:;8:; C1 Univ Nevada, Dept Geosci, Las Vegas, NV 89154 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Univ Massachusetts, Dept Geosci, Amherst, MA 01003 USA. Univ Saskatchewan, Dept Geol Sci, Saskatchewan Isotope Lab, Saskatoon, SK S7N 5E2, Canada. C2 UNIV NEVADA, USA UNIV NEW MEXICO, USA UNIV MASSACHUSETTS, USA UNIV SASKATCHEWAN, CANADA IF 4.245 TC 28 UR https://archimer.ifremer.fr/doc/00219/33020/31488.pdf LA English DT Article CR MD 126 / MONA BO Marion Dufresne AB We present a high-resolution terrestrial archive of Central American rainfall over the period 100-24 and 8.1-6.5 ka, based on delta(18)O time series from U-series dated stalagmites collected from a cave on the Pacific Coast of Costa Rica. Our results indicate substantial delta(18)O 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. PY 2009 PD DEC SO Quaternary Science Reviews SN 0277-3791 PU Pergamon-elsevier Science Ltd VL 28 IS 27-28 UT 000273195700024 BP 3348 EP 3360 DI 10.1016/j.quascirev.2009.09.018 ID 33020 ER EF